Presentation on theme: "Periodic Table The Noble Gases"— Presentation transcript:
1 Periodic Table The Noble Gases At the start of the 1890s, no one had any idea that there was a separate group of gases in the periodic table, the noble gases. Noble gases are familiar to us from their use in neon signs and helium balloons. By 1900 this whole new group had been identified and isolated. While trying to determine an accurate atomic mass for nitrogen, British physicist Lord Raleigh ( ) discovered that nitrogen prepared from ammonia was noticeably lighter than nitrogen that came from the atmosphere. He and William Ramsay ( ) both studied “atmospheric” nitrogen. By removing the nitrogen from it, they produced a tiny quantity of another gas. Since it did not react with anything they called it argon, from the Greek word for lazy. The discovery of helium followed a year later in Ramsay and his assistant Morris Travers ( ) then started to search for additional elements in this new group. They attempted this by fractional distillation of large quantities of liquid air and argon. In 1898, their efforts were rewarded; they had prepared krypton, neon, and xenon.Eyewitness Science “Chemistry” , Dr. Ann Newmark, DK Publishing, Inc., 1993, pg 32Kelter, Carr, Scott, Chemistry A Wolrd of Choices 1999, page 74
3 Guiding Questions Why is the periodic table so important? Why is the periodic table shaped the way it's shaped?Why do elements combine? Why do elements react?What other patterns are there in the world and how dothey help us?Periodic Table Study Questions1. Why did chemists make the periodic table?2. Why was the table difficult to make?3. Why were Dobereiner’s triads of limited use at a periodic table?4. What did Newland discover about the elements?5. What did Meyer contribute to the development of the periodic table?6. What did Mendeleev use as the organizing property for the periodic table?7. What problem developed from the use of this property?8. What is common to elements in a column of the table?9. How did properties change in a row of the table?10. What was the significance of gaps in Mendeleev’s periodic table?11. What did Moseley use to order the elements in the periodic table?12. How did Moseley change the periodic law?13. What determines the identity of an element?14. Why do elements in a column of the periodic table have similar properties?15. With respect to the Periodic Table, what is the meaning of periodic?16. What does a row of the Periodic table represent?17. What happens to valence electrons as you move left to right in a row?18. When determines stability in an atom?19. List, from least to most, the stable configurations in an atom.20. What determines the column of the periodic table an element is in?21. What sublevels are in the outer level of an atom?22. What is the maximum number of electrons in the outer level of an atom?23. What determines the row and column of the periodic table an element is in?24. What are common properties of metals?25. What are common properties of non-metals?26. What three things can happen to electrons when atoms form compounds?27. The configuration of He is 1s2, but it is placed in column 18. Explain this discrepancy.28. Hydrogen is obviously not an alkali metal. Why is it in column 1 of the table?29. What is necessary for a metalloid to act as a semiconductor?
4 Table of Contents ‘Periodic Table’ How to Organize ElementsMendeleev’s Periodic TableModern Periodic TableGroups of ElementsMetals, Nonmetals, MetalloidsDiscovering ElementsOrigin of Names of ElementsSelected ElementsElectron Filling OrderDiatomic MoleculesSize of Atoms – TrendsIonization EnergySummary of Periodic TrendsEssential ElementsElement ProjectWhen elements are listed in order according to the number of protons, repeating patterns of physical and chemical properties result and can be used to make predictionsThe ability to create a model and then make predictions that prove to be correct, based upon that model, is what science is all about.More Specifically...:HistoryDescribe the contributions of Mendeleev and Mosley on the periodic tablea. periodic table by atomic mass and property - Dimitri Mendeleevb. periodic table by atomic number - Henry MoseleyTrends - Physical PropertiesAssociate rows with periods and columns with families or groups.Identify the seven diatomic gasesGive locations and list characteristic properties of metals, non-metals, metalloids, and noble gases.Label the following areas on a periodic charta. Alkali metalsb. Alkaline Earth Metalsc. Transition Metalsd. Metalloidse. Halogensf. Noble gasesg. Lanthanidesh. ActinidesTrends - Chemical PropertiesDefine and give the general trends on the periodic table fora. Ionization energyb. Electronegativityc. Atomic radius / Ion radiusd. Electron affinitye. ReactivityDefine shielding effect and use it to explain trends in familiesDefine effective nuclear charge and use it to explain trends in periodsPredict location on periodic table given ionization energy dataState that the noble gas configuration is the most stable electron configurationPredict oxidation states for various elements based on their proximity to a noble gas in the periodic tableWrite electron configurations and orbital diagrams of ions
5 Atomic Structure and Periodicity You should be able toIdentify characteristics of and perform calculations with frequency andwavelength.Know the relationship between types of electromagnetic radiation andEnergy; for example, gamma rays are the most damaging.Know what exhibits continuous and line spectra.Know what each of the four quantum numbers n, l, m, and ms represents.Identify the four quantum numbers for an electron in an atom.Write complete and shorthand electron configurations as well as orbitaldiagrams for an atom or ion of an element.Identify the number and location of the valence electrons in an atom.Apply the trends in atomic properties such as atomic radii, ionizationenergy, electronegativity, electron affinity, and ionic size.Fast Track to a 5 (page 61)OBJECTIVES:To become familiar with the history of the periodic tableTo understand periodic trends in atomic radiiTo be able to predict relative ionic sizes within an isoelectronic seriesTo correlate ionization energies and electron affinities with the chemistry of the elementsTo become familiar with the relationship between the electronegativity of an element and its chemistryTo understand the correlation between the chemical properties and the reactivity of the elements and their positions in the periodic tableTo be able to describe some of the roles of trace elements in biological systemsPeriodic Properties -Study Questions1. What 4 things determine how properties change?2. What two properties determine the reaction tendency of an element?3. What is atomic radius?4. What are the patterns for atomic radius in the periodic table?5. What two factors determine the force felt by the outer electrons?6. What is the shielding effect?7. What two factors cause atomic radius to increase in the elements of a column?8. What causes the atomic radius to decrease across a row?9. Why are the noble gas atoms larger than expected?10. What configuration is found in ions?11. Why is a positive ion smaller than its atom?12. Why is a negative ion larger than its atom?13. What is an oxidation number?14. What is the pattern for oxidation numbers?15. What property determines the reactivity of the metals?16. What property determines the reactivity of the non-metals?17. What is ionization energy?18. What factors affect ionization energy?19. What are the patterns for ionization energy in the periodic table?20. Why do these patterns form?21. Why are second and higher ionization energies higher?22. Why do the alkali metals react violently with H2O?23. Why are the alkaline earth metals less reactive than the alkali metals?24. What is electron affinity?25. What factors influence electron affinity?26. Why does electron affinity drop down a column?27. What happens to electron affinity across a row and why?28. Explain why Be, N, and Ne are exceptions to the trends.29. Why does ionization energy have the greatest effect on the reactivity of metals?30. Why does electron affinity have the greatest effect on the reactivity of non-metals?
6 Vocabulary - Periodic Table Vocabulary: Periodic Table and PeriodicityVocabulary: Periodic Table and PeriodicityKeys
7 Lecture Outline – Periodicity student notes outlinetextbook questions(key)Lecture Outline – PeriodicityALL students should;Know what are meant by the terms, "group" and "period", when applied to the periodic tableBe able to recall the group names of groups 1A (1), 2A (2), 7A (17) and 8A (18)Understand that regular, repeatable patterns occur in the periodic tableAppreciate that these patterns sometimes have notable exceptionsRecall and understand that the noble gases have full outer shells that represent stable electronic configurationsRecall how, and understand why, group 1A, 2A, 6A and 7A elements achieve pseudo noble gas electronic configurationsRecall the definition of ionization energyRecall the definition of electron affinityRecall and understand the variation in ionization energy and electron affinity when moving about the periodic tableBe able to predict the group an element is in from ionization energy dataRecall how and why atomic and ionic size vary when moving about the periodic tableUnderstand how many physical properties change gradually when moving about the periodic tabletextbook questionsKeystext
8 Chemistry: The Periodic Table and Periodicity KeyClick Here for COPYChemistry: The Periodic Table and Periodicity1. Who first published the classification of the elements that is the basis of our periodic table today?2. By what property did Mendeleev arrange the elements?3. By what property did Moseley suggest that the periodic table be arranged?4. What is the periodic law?5. What is a period? How many are there in the periodic table?6. What is a group (also called a family)? How many are there in the periodic table?DMITRI MENDELEEVATOMIC MASSATOMIC NUMBERTHE PROPERTIES OF THE ELEMENTS REPEAT PERIODICALLYA HORIZONTAL ROW IN THE PERIODIC TABLE; 7A VERTICAL COLUMN IN THE PERIODIC TABLE; 18
9 7. State the number of valence electrons in an atom of: a. sulfur b. calcium c. chlorine d. arsenic8. Give the names and chemical symbols for the elements that correspond tothese atomic numbers:a. 10 b. 18 c. 36 d. 909. List, by number, both the period and group of each of these elements.Symbol Period Groupa. beryllium Beb. iron Fec. lead Pb10. Which of the following pairs of elements belong to the same period?a. Na and Cl b. Na and Li c. Na and Cu d. Na and Ne11. Which of the following pairs of elements belong to the same group?a. H and He b. Li and Be c. C and Pb d. Ga and Ge12. How does an element’s period number relate to the number of the energylevel of its valence electrons?6275Ne, NEONAr, ARGONKr, KRYPTONTh; THORIUM2248614a. Na and Clc. C and PbPERIOD NUMBER = ENERGY LEVEL OF VALENCE ELECTRONS
10 13. What are the transition elements? 14. In what type of orbitals are the actinide and lanthanide electrons found?15. Would you expect strontium to be, chemically, more similar to calcium or rubidiumand WHY?16. What are the coinage elements?17. What is the heaviest noble gas? What is the heaviest alkaline earth metal?18. In going from top to bottom of any group, each element has more occupiedenergy level(s) than the element above it.GROUPS 3-12f-ORBITALSCa; BOTH Ca AND Sr HAVE TWO VALENCE ELECTRONSGROUP 11; Cu, Ag, AuRADON (Rn);RADIUM (Ra)ONE19. What are the Group 1 elements called?20. What are the Group 2 elements called?21. What are the Group 17 elements called?22. What are the Group 18 elements called?23. What is the name given to the group of elements that have the following valence shell electron configurations?a. s b. s2p6c. s2p d. s1ALKALI METALSALKALINE EARTH METALSHALOGENSNOBLE GASESALKALINE EARTH METALSNOBLE GASESHALOGENSALKALI METALS
11 24. List the three lightest members of the noble gases. 25. List all of the alkali metals.26. Which alkali metal belongs to the sixth period?27. Which halogen belongs to the fourth period?28. What element is in the fifth period and the eleventh group?29. Why do all the members of a group have similar properties?30. What do we mean by the “atomic radius?”31. Within a group, what happens to the atomic radius as you go down the column?32. Explain your answer to Question 31: Why does the atomic radius change?He, Ne, ArLi, Na, K, Rb, Cs, FrCsBrAgTHEY HAVE THE SAME NUMBER OF VALENCE ELECTRONSTHE SIZE OF A NEUTRAL ATOMINCREASESELEMENT BELOW HAS ONE MORE ENERGY LEVEL THAN ELEMENT ABOVE
12 33. What is coulombic attraction? 34. Within a period, what happens to the atomic radius as the atomic number increases?35. Explain your answer to Question 34: Why does the atomic radius change?36. What two factors determine the strength of coulombic attraction?37. What is the shielding effect?38. How are the shielding effect and the size of the atomic radius related?ATTRACTION OF (+) AND (–) CHARGESDECREASESNO ADDITIONAL ENERGY LEVELS,BUT MORE (+) AND (–) CHARGES = MORE PULLAMOUNT OF CHARGE; DISTANCE BETWEEN CHARGESKERNEL ELECTRONS “SHIELD” VALENCE ELECTRONS FROMATTRACTIVE FORCE OF THE NUCLEUS; CAUSED BY KERNELAND VALENCE ELECTRONS REPELLING EACH OTHERAS RADIUS INCREASES, SHIELDING EFFECT INCREASES(MORE SHELLS OF KERNEL e– TO REPEL VALENCE e–)
13 39. How are neutral atoms converted into cations? How are neutral atoms converted into anions?40. Metals usually form what type of ions?Nonmetals usually form what type of ions?41. What is ionization energy?42. What is the equation that illustrates ionization energy, and what does each symbol represent?43. What do we mean by the first, second, and third ionization energies for a particular atom?44. Why does each successive ionization require more energy than the previous one?45. What is the general trend of ionization energy as you go from left to right across the periodic table?46. What is the general trend of ionization energy as you go down a group on the periodic table?LOSE ELECTRONSACQUIRE ELECTRONSCATIONSANIONSTHE ENERGY REQUIRED TO REMOVE AN ELECTRON FROM AN ATOMM (g) ionization energy M1+(g) e–ENERGY REQUIRED TO REMOVE THE 1st, 2nd, AND 3rd ELECTRONS(+) NUCLEUS HOLDS ON TIGHTER TO THE FEWER REMAINING ELECTRONSINCREASESDECREASES
14 48. When an atom becomes an anion, what happens to its radius? 47. Which of these elements has the highest first ionization energy: Sn, As, or S?48. When an atom becomes an anion, what happens to its radius?49. When an atom becomes a cation, what happens to its radius?50. For each of the following pairs, circle the atom or ion having the larger radius.a. S or O c. Na1+ or K1+ e. S2– or O2–b. Ca or Ca2+ d. Na or K f. F or F1–51. For each of the following pairs, identify the smaller ion.a. K1+ or Ca2+ c. C4+ or C4– e. O2– or F1–b. F1– or Cl1– d. S2– or F1– f. Fe2+ or Fe3+52. Where, generally, are the metals located on the periodic table?53. Where, generally, are the nonmetals located on the periodic table?54. A. List some properties of metals.B. List some properties of nonmetals.C. What kinds of properties do metalloids have?SBECOMES LARGERBECOMES SMALLERSK1+S2–CaKF1–LINKCa2+C4+LINKF1–F1–F1–Fe3+ON THE LEFTON THE RIGHTGOOD CONDUCTORS; MALLEABLE; DUCTILE; LUSTROUS SOLIDSGOOD INSULATORS; DULL, BRITTLE SOLIDS (OR GASES)PROPERTIES OF BOTH METALS AND NONMETALS
15 > Potassium atom = [Ar]4s1 Calcium atom = [Ar]4s2 p = 19 n = 20 e = 19p = 20n = 20e = 20K e K1+Ca 2 e Ca2+Potassium ion = K1+ ≡ [Ar]1s22s22p63s23p6Calcium ion = Ca2+ ≡ [Ar] or1s22s22p63s23p619e-18e->20e-18e-19+20+
16 < Oxygen atom = [He]2s22p4 Fluorine atom = [He] 2s22p5 p = 8 n = 8 O e- O2-F + e- F1-Oxide ionOxygen ion = O2- ≡ [Ne]1s22s22p6Fluoride ionFluorine ion = F1- ≡ [Ne]1s22s22p68 e-6 e-<7 e-8 e-8+9+
17 55. What is electronegativity? 56. Who determined the scale of electronegativity most often used today?57. List the following atoms in order of increasing electronegativity: O, Al, Ca58. List the following atoms in order of decreasing electronegativity: Cl, K, Cu59. What is the general trend of electronegativity as you go down the periodic table?60. What is the general trend of electronegativity as you go left to right across the periodic table?THE TENDENCY FOR AN ATOM TO ATTRACT ELECTRONS TO ITSELFLINUS PAULINGCa < Al < OCl > Cu > KDECREASESINCREASES
18 World of Chemistry The Annenberg Film Series VIDEO ON DEMANDEpisode 7 – The Periodic TableThe development of the Periodic Table of Elements produced order from the chaos of disorganized amounts of chemical information.The program shows the power of Mendeleev’s arrangements, which predicted the properties of as yet undiscovered elements, andhow modern chemists have refined its arrangement and continue to refer to the Periodic Table.Video 07: Periodic Table The development and arrangement of the periodic table of elements is examined. (added 2006/10/08) World of Chemistry >Journey through the exciting world of chemistry with Nobel laureate Roald Hoffman as your guide.The foundations of chemical structures and their behavior are explored through computer animation,demonstrations, and on-site footage at working industrial and research labs. Distinguished scientistsdiscuss yesterday’s breakthroughs and today’s challenged.Produced by the University of Maryland and the Educational Film Center.Released on cassette: Fall The Annenberg/ / CPB Collection LEARNER
19 Energy Level Diagram of a Many-Electron Atom 6s p d f325s p d184s p dArbitraryEnergy Scale183s p8Original reference: Pimental, Chemistry An Experimental Science, (CHEM Study), 1969, page 266.2s p81s2NUCLEUSO’Connor, Davis, MacNab, McClellan, CHEMISTRY Experiments and Principles 1982, page 177
20 How to Organize Elements… Periodic Table Designs
21 Which way is CORRECT to organize the elements? How to Organize…Baseball Cards:year, team, player, card number, value ($).Elements:when they were discovered, family, reactivity,state of matter, metal vs. non-metal, atomic mass,atomic number.alphabetically, mass, value, density, solid or liquid or gasWhich way is CORRECT to organize the elements?Is it possible to organize the elements correctly in more than one way?
22 N C H S Ir O N Mn The Human Element H He H Li Be B C N O F Ne Na Mg Al Interactive Periodic TableN7C6H1eS16Ir77O8N7Mn25<H1He2H1The Human Element1Li3Be4B5C6N7O8F9Ne102Na11Mg12Al13Si14P15S16Cl17Ar183K19Ca20Sc21Ti22V23Cr24Mn25Fe26Co27Ni28Cu29Zn30Ga31Ge32As33Se34Br35Kr364Rb37Sr38Y39Zr40Nb41Mo42Tc43Ru44Rh45Pd46Ag47Cd48In49Sn50Sb51Te52I53Xe545Cs55Ba56Hf72Ta73W74Re75Os76Ir77Pt78Au79Hg80Tl81Pb82Bi83Po84At85Rn866*A periodic table by itself is not that interesting. It is when we add the "human element", i.e. you and me, that chemistry becomes interesting.And just like that, the laws of chemistry change. A world that includes the Human Element, along with hydrogen, oxygen and other elements, is a very different world indeed. Suddenly, chemistry is put to work solving human problems. Bonds are formed between aspirations and commitments. And the energy released from reactions fuels a boundless spirit that will make the planet a safer, cleaner, more comfortable place for generations to come. A world that welcomes change is about to meet the element of change: the Human Element.By itself, a human body is worth very little (perhaps $5.00 as elements). When we look at the incredible enzymes and hormones in the body we can see we are worth ~millions of dollars.Fr87Ra88Rf104Db105Sg106Bh107Hs108Mt1097WLa57Ce58Pr59Nd60Pm61Sm62Eu63Gd64Tb65Dy66Ho67Er68Tm69Yb70Lu71Ac89Th90Pa91U92Np93Pu94Am95Cm96Bk97Cf98Es99Fm100Md101No102Lr103
23 Aliens Activity Look carefully at the drawings of the ‘aliens’. Nautilus shell has a repeating pattern.Look carefully at the drawings of the ‘aliens’.Organize all the aliens into a meaningful pattern.Aliens Lab Cards
24 Periodic Table 8A 1A He H 3A 4A 5A 6A 7A 2A B C N O F Ne Li Be Si P S Alkali metalsAlkali earth metalsHe2H111Transition metals3A4A5A6A7A2ABoron groupB5C6N7O8F9Ne10Li3Be4Nonmetals22Noble gasesSi14P15S16Cl17Ar18Na11Mg12Al13338B3B4B5B6B7B1B2BAs33Se34Br35Kr36K19Ca20Sc21Ti22V23Cr24Mn25Fe26Co27Ni28Cu29Zn30Ga31Ge3244Te52I53Xe54Rb37Sr38Y39Zr40Nb41Mo42Tc43Ru44Rh45Pd46Ag47Cd48In49Sn50Sb5155At85Rn86Cs55Ba56Hf72Ta73W74Re75Os76Ir77Pt78Au79Hg80Tl81Pb82Bi83Po8466Fr87Ra88Rf104Db105Sg106Bh107Hs108Mt10977Lanthanoid Series6La57Ce58Pr59Nd60Pm61Sm62Eu63Gd64Tb65Dy66Ho67Er68Tm69Yb70Lu71CSolidActinoid SeriesBrLiquid7Ac89Th90Pa91U92Np93Pu94Am95Cm96Bk97Cf98Es99Fm100Md101No102Lr103HGas
25 Dutch Periodic Table118117116115114113112111110109108107106Strong, Journal of Chemical Education, Sept. 1989, page 743
28 Döbereiner’s Triads Name Atomic Mass Calcium 40 Barium 137 Johann Döbereiner~1817NameAtomicMassCalciumBariumAverageStrontiumChlorineIodineAverageBromineSulfurTelluriumAverageSeleniumDöbereiner found that the properties of the metals calcium, barium, and strontium were very similar.He also noted that the atomic mass of strontium was about midway between those of calcium and barium.Döbereiner discovered groups of three related elements which he termed a triad.Döbereiner discovered groups of three related elements which he termed a triad.Smoot, Price, Smith, Chemistry A Modern Course 1987, page 161
29 Newlands Law of Octaves John Newlands~1863Newlands Law of Octaves1LiNaK2BeMg3BAl4CSi5NP6OS7FClJohn Newlands, suggested another classification. He arranged the elements in order of their increasing atomic masses. He noted that there appeared to be a repetition of similar properties for every eighth element. Therefore, he arranged the elements known at that time into seven groups of seven each. [Noble gases were not known at the time]. Newland’s referred to his arrangement as the law of octaves.Newland’s law of octaves was proposed to explain the properties which occurred with every eighth element when the elements were arranged in order of increasing atomic mass.Smoot, Price, Smith, Chemistry A Modern Course 1987, page 161
30 Development of Periodic Table J.W. Döbereiner (1829)Law of TriadsElements could be classified into groups of three, or triads.Trends in physical properties such as density, melting point,and atomic mass were observed.J.A.R. Newlands (1864)Law of OctavesArranged the 62 known elements into groups of sevenaccording to increasing atomic mass.He proposed that an eighth element would then repeat theproperties of the first element in the previous group.The Periodic Table“As new elements were discovered, their atomic masses were determined, and the way each reacted with other substances was studied. Chemists began to notice families of elements that showed similar behavior. As early as 1829 Johan Döbereiner ( ) had introduced the idea of triads of elements (groups of three): thus lithium, sodium, and potassium, all similar metals, formed one group, and they tended to behave in the same way. The Russian chemist Dmitri Mendeleyev ( ) observed that elements listed in order of atomic mass showed regularly (or periodically) repeating properties. He announced his Periodic Law in 1869 and published a list of known elements in a tabular form. He had the courage to leave gaps where the Periodic Law did not seen to fit, predicting that new elements would be discovered to fill them.”The modern periodic table has evolved through a long history of attempts by chemists to arrange the elements according to their properties as an aid in predicting chemical behavior.Johannes Döbereiner in circa 1800 noticed that many of the known elements could be grouped in triads, sets of three elements that have similar properties.In the early 1800's Dobereiner noted that similar elements often had relative atomic masses, and DeChancourtois made a cylindrical table of elements to display the periodic reoccurrence of properties.By the mid-nineteenth century, John Newlands hypothesized that the chemistry of the elements might be related to their masses and arranged the known elements in order of increasing atomic mass and found that every seventh element had similar properties. Newlands suggested that the elements could be classified into octaves, corresponding to the horizontal rows in the main group elements, but this did not seem to work for elements heavier than calcium.Cannizaro determined atomic weights for the 60 or so elements known in the 1860s, then a table was arranged by Newlands, with the elements given a number in series in order of their atomic weights, beginning with Hydrogen. This made evident that "the eighth element, starting from a given one, is a kind of repetition of the first", which Newlands called the Law of Octaves.Both Meyer and Mendeleyev constructed periodic tables independently that are credited as being the basis of the modern table. Meyer was more impressed by the periodicity of physical properties, while Mendeleyev was more interested in the chemical properties.“No one foresaw the discovery of an entirely new group of elements in the 1890’s. They were added as a separate column. The periodic table did not immediately have an impact on chemical theory until the discovery of missing elements.”The periodic table achieved its modern form through the work of Julius Meyer and Dimitri Mendeleev, who focused on the relationships between atomic mass and various chemical properties.Mendeleyev published his periodic table & law in 1869 and forecast the properties of missing elements, and chemists began to appreciate it when the discovery of elements predicted by the table took place. Periodic tables have always been related to the way scientists thought about the shape and structure of the atom, and has changed accordingly. Dimitri Mendeleyev"...if all the elements be arranged in order of their atomic weights a periodic repetition of properties is obtained." - MendeleyevMendeleev had gained considerable notoriety by boldly predicting chemical properties of certain undiscovered elements.In 1869, they independently proposed essentially identical arrangements of the elements. The periodic law appears to have been discovered by at least six people independently within the one decade - Mendeleyev, Lothar Meyer, Hinrichs, Odling, Newlands, and De Chancourtois.Meyer aligned the elements according to periodic variations in simple atomic properties such as atomic volume, which he obtained by dividing the atomic mass (molar mass) in grams per mole by the density of the element in grams per cubic centimeter:molar mass (g/mol)density (g/cm3) = molar volume (cm3/mol)The `modern' periodic table is very much like a later table by Meyer, arranged, as was Mendeleyev's, according to the size of the atomic weight, but with Group 0 added by Ramsay. Later, the table was reordered by Mosely according to atomic numbers (nuclear charge) rather than by weight.-Eyewitness Science “Chemistry” , Dr. Ann Newmark, DK Publishing, Inc., 1993, pg 23Newlands (English chemist) idea was rejected by the scientific community for ~20 years. In 1887, Newlands accepted the Davy Medal from the Royal Society of Great Britain.Only 30 elements had been isolated and identified.known elementsLothar Meyer (German chemist)Lothar Meyer (1830 – 1895)Invented periodic table independently of Mendeleevhis work was not published until one year after Mendeleev's
31 Mendeleev’s Periodic Table Objective:To state the original periodic law proposed by Mendeleev."Ich bin Mendelejeff"Once there lived and existed a great learned man with a beard almost as long as God's. And one day the people came to this man and said 'Go to the Lord, and tell him of our misery.' 'I will go,' said the man. So he caught a great bubble, and sat down on top of it, and flew up and up until he pierced the heaven above us. And there he saw God and told him of our misery and God pardoned our sins and lightened our burdens. Then the great bearded man came down from the heavens and the people were happy. And for this, the authorities and the tsar made this man a very great scientist. (16) Dmitri Ivanovich Mendeleev was born in Tobolsk, Siberia, on February 7, 1834 (ns). The blonde-haired, blue-eyed boy was the youngest of 14 children (or 11 or 17, depending on the authority) born to Maria Dmitrievna Korniliev and Ivan Pavlovitch Mendeleev. His father (called Mendeleev because early in life he dealt in horses, "mjenu djelatj" = to make an exchange(4)) was director of the local gymnasium. Maria Korniliev's family settled in Tobolsk in the early 1700's and introduced paper- and glass-making to Siberia.(4) Unfortunately, Ivan died when Dmitri was quite young, leaving his wife to support the large family. The pension for educators at that time (1000 rubles) was drastically insufficient, especially for a large family, which meant that Maria had no other choice but to find work. Maria's family owned a glass factory in Aremziansk, and they allowed her to take over managing the company for a modest wage from which she could support the family.Dmitri, being the youngest, appears to have been his mother's favorite child and was provided as many opportunities as she could afford. From his early years, she began to save money for Dmitri to attend the university. However, it was not only his mother who offered him special favors. He spent many hours in the glass factory his mother operated, learning from the chemist about the concepts behind glass making and from the glass blower about the art of making glass. Another influence in Dmitri's life was his sister Olga's husband, Bessargin. After being banished to Siberia for his political beliefs as a Russian Decembrist (Dekabrists, a group of literary men who headed a revolution in 1825(4),), Bessargin occupied himself teaching Dmitri the science of the day. Mendeleev's early years were guided by these people, and he was thus raised with three key thoughts:"Everything in the world is science," from Bessargin "Everything in the world is art," from Timofei the glass blower. "Everything in the world is love," from Maria his mother. (16) As he grew older, it became apparent that he had exceptional comprehension of complex topics. At the age of 14, he was attending the Gymnasium in Tobolsk and his mother was continuing to plan for his future. In that year, however, a second major family tragedy occurred; the glass factory burned to the ground. The family was devastated; there was no money to rebuild and the only money they had was the money saved for Dmitri to go to the university. Maria was not about to give up her dreams for her son. She knew at this point that Dmitri's only hope to go on to school was to win a scholarship. So in his final years at the gymnasium, Maria pushed Dmitri to improve his grades and prepare for entrance exams.This was no easy task, as Dmitri was not a "classical" scholar. He knew at a very young age that he wanted to study science and saw very little need for studying topics such as Latin and history. He felt that these were dead topics and a waste of his time. After much coaxing from his mother and Bessargin, Mendeleev passed his gymnasium exams and prepared to enter the university. This disdain of the "classical" education was to color his later writings on education when, in 1901, he stated:...We could live at the present day without a Plato, but a double number of Newtons is required to discover the secrets of nature, and to bring life into harmony with the laws of nature. (4) In 1849, with nothing left for the family at Aremziansk, Maria loaded up the family's belongings and headed for Moscow. At this point the family included Maria, Dmitri, and Elizabeth (Dmitri's older sister). In Moscow, they entered a climate of considerable political unrest, which made the university reluctant to admit anyone from outside of Moscow. Mendeleev was rejected. Maria did not give up, however, and the family headed for St. Petersburg.Again, they encountered similar turmoil but this time they found a friend of Ivan's working at the Pedagogical Institute, his father's school. With a little persuasion, Dmitri was allowed to take the entrance exams, which he passed, not with honors but well enough to be admitted to the science teacher training program on a full scholarship. He entered the university in the fall of 1850.Maria died shortly after Dmitri's acceptance at St. Petersburg, followed a few short months later by Elizabeth; both died from tuberculosis. Mendeleev was left alone to face his work at the university, but was to later eulogize his mother in his book on Solutions:This investigation is dedicated to the memory of a mother by her youngest offspring. Conducting a factory she could educate him only by her own work. She instructed by example, corrected with love, and in order to devote him to science she left Siberia with him, spending thus her last resources and strength. When dying she said, 'Refrain from illusions, insist on work and not on words. Patiently search divine and scientific truth.' She understood how often dialectical methods deceive, how much there is still to be learned, and how, with the aid of science without violence, with love but firmness, all superstition, untruth and error are removed, bringing in their stead the safety of undiscovered truth, freedom for further development, general welfare, and inward happiness. Dmitri Mendeleev regards as sacred a mother's dying words. (19)Dmitri fell right into his work at St. Petersburg. His studies progressed rapidly until his third year. At that point he was struck with an illness that caused him to be bedridden for the next year. He continued his studies, however, with professors and fellow students visiting him to give him assignments, etc. Mendeleev graduated on time and was awarded the medal of excellence for being first in his class. Dmitri's illness did not improve. His doctor suggested that he had tuberculosis and that, at most, he had two years to live providing he moved to a more suitable climate. Mendeleev already had his life's ambitions in mind and, hoping to extend his life as long as possible, he moved to Simferopol in the Crimean Peninsula near the Black Sea in 1855 as chief science master of the gymnasium. He was 21 years old. At this point in his life he was driven by "the vision of the Russian people whom he knew he could aid through science." Needless to say, his move to the south was very beneficial. He progressively regained his strength to the point where the doctors found no sign of tuberculosis in his system.In 1856, Mendeleev returned to St. Petersburg and defended his master's thesis: "Research and Theories on Expansion of Substances due to Heat." Following his masters program, Dmitri focused his life on his career of teaching and research. He was essentially a teacher devoted to his work and to his students; he was next a lover of his country and of his fellow men. The first led to his books and the periodic table, while the latter gave rise to his studies of chemical technology and the organization of Russia's industries, agriculture, transport meteorology and metrology. (17)In 1859, he was assigned by the Minister of Public Instruction to go abroad to study and develop scientific and technological innovations. Between 1859 and 1861 he studied the densities of gases with Regnault in Paris and the workings of the spectroscope with Kirchoff in Heidelberg. He also pursued studies of capillarity and surface tension that led to his theory of "absolute boiling point," later known as critical temperature. While in Heidelberg he made the acquaintance of A.P. Borodin, a chemist who was to achieve greater reknown as a composer.(9) In 1860 at the Chemical Congress at Karlsruhe, Mendeleev had the opportunity to hear Cannizzaro discuss his work on atomic weights. These people greatly influenced the work which Mendeleev would pursue the rest of his life.Following his trip abroad, the Russian chemist returned to his homeland where he settled down to a life of teaching and research in St. Petersburg. In 1863 he was named Professor of Chemistry at the Technological Institute and, in 1866, he became Professor of Chemistry at the University and was made Doctor of Science for his dissertation "On the Combinations of Water with Alcohol". As will be seen, his research findings were expansive and beneficial to the Russian people. Dmitri was always in touch with the classroom. Much of his lab work, including that on the periodic chart, occurred in his spare time following his lectures. He truly enjoyed educating the people, and they, in turned enjoyed his efforts:...For me it was a revelation, a beautiful improvisation, a stimulant to the intellect which left deep traces on my development. (16) Mendeleev not only taught in the university classrooms but anywhere he travelled. Many excerpts discuss his journeys by train where he would travel third class with the mouzhiks (peasants). It was on those journeys that he would share his findings about agriculture with the peasants over a cup of tea. The admiration that Mendeleev had for the people of Russia was reciprocated by the people. On the trains the mouzhiks would all gather round to see and talk with the man. The university students also adored him. Crowds of students would fill lecture halls to hear him speak of chemistry.For Mendeleev, science was always the most important subject, but in that time period of unrest, just as today, science could be expanded to the realms of politics and social inequality. Mendeleev was not afraid to express his views on these topics:> There exists everywhere a medium in things, determined by equilibrium. The Russian proverb says, 'Too much salt or too little salt is alike an evil.' It is the same in political and social relations... It is the function of science to discover the existence of a general reign of order in nature and to find the causes governing this order. And this refers in equal measure to the relations of man - social and political - and to the entire universe as a whole. (16) These profound thoughts of order led him to the discovery of the periodic law, among other things, but also led to his resignation from the University on August 17, Throughout his life he witnessed a country repressed and in turmoil. As he grew older and more famous, he used his new-found prestige and power to try to speak out against repression.The most all penetrating spirit before which will open the possibility of tilting not tables, but planets, is the spirit of free human inquiry. Believe only in that. (16) His resignation from the university came as the result of carrying a student petition to the Minister of Education. The Minister refused to acknowledge the requests, stating that Mendeleev should keep to teaching and not involve himself with students and politics. Mendeleev's final lecture at the University of St. Petersburg was broken up by police who feared that he might lead the students in an uprising.Dmitri's personal life also appears to have been in turmoil for many years. In 1863, with the heavy influence of his sister Olga, Dmitri married Feozva Nikitchna Lascheva. They had two children, a boy named Volodya, and a daughter named Olga. Mendeleev never really loved Feozva and actually spent little time with her. One story suggests that, at one point in their life together, Feozva asked Mendeleev if he was married to her or to science; his response was that he was married to both unless that was bigamy, in which case he was married to science. In January 1882, he divorced Feozva so he could marry his niece's best friend, Anna Ivanova Popova. According to the Orthodox Church, Mendeleev was officially a bigamist; however, he was so famous in Russia that the Czar said "Mendeleev has two wives, yes, but I have only one Mendeleev".(11) Anna was considerably younger than Dmitri but the two loved each other very much and were together until his death. They had four children: Liubov, Ivan, and twins Vassili and Maria. Anna also had considerable influence over Mendeleev's views on art, and he was elected to the Academy of Arts for both his insightful criticism and his painting.As he grew older it also became apparent that personal appearance became less and less significant to him. Many stories abound relating to the idea that in his later years, Dmitri would only cut his hair and beard once a year. He would not even cut it by request of the tsar. One observer stated, "Every hair acted separate from the others." It becomes apparent that, in most respects, work came first for Dmitri Mendeleev.From his first publication in 1854 entitled "Chemical Analysis of a Sample from Finland" to his final works in 1906 such as "A Project for a School for Teachers" and "Toward Knowledge of Russia", Mendeleev's transcripts revealing his research findings and beliefs number well over 250. His most famous publications include Organic Chemistry, which was published in 1861 when he was 27 years old. This book won the Domidov Prize and put Mendeleev on the forefront of Russian chemical education. The first edition of Principles of Chemistry was printed in Both of these books are classroom texts. Again, Mendeleev never lost sight of the importance of education.Besides his work on general chemical concepts as discussed earlier, Mendeleev spent much of his time working to improve technological advances of Russia. Many of his research findings dealt with agricultural chemistry, oil refining, and mineral recovery. Dmitri was also one of the founding members of the Russian Chemical Society in 1868, and helped open the lines of communication between scientists in Europe and the United States.Mendeleev also pursued studies on the properties and behavior of gases at high and low pressures, which led to his development of a very accurate differential barometer and further studies in meteorology. He also became interested in balloons, which led to a rather perilous adventure in In order to observe the solar eclipse above Klin, he made a solo ascent, without any prior experience; while his family was rather concerned, he paid no attention to controlling the balloon until after he had completed his observations, at which time he figured out how to land his conveyance. (4,9)His greatest accomplishment, however, was the stating of the Periodic Law and the development of the Periodic Table. From early in his career, he felt that there was some type of order to the elements, and he spent more than thirteen years of his life collecting data and assembling the concept, initially with the idea of resolving some of the chaos in the field for his students. Mendeleev was one of the first modern-day scientists in that he did not rely solely on his own work but rather was in correspondence with scientists around the world in order to receive data that they had collected. He then used used their data along with his own data to arrange the elements according to their properties.No law of nature, however general , has been established all at once; its recognition has always been preceded by many presentiments. The establishment of a law, moreover, does not take place when the first thought of it takes form, or even when its significance is recognised, but only when it has been confirmed by the results of the experiment. The man of science must consider these results as the only proof of the correctness of his conjectures and opinions. (9) In 1866, Newlands published a relationship of the elements entitled the "Law of Octaves". Mendeleev's ideas were similar to those of Newlands but Dmitri had more data and felt that Newlands had not gone far enough in his research. By 1869, the Russian chemist had assembled detailed descriptions of more than 60 elements and, on March 6, 1869 a formal presentation was made to the Russian Chemical Society entitled "The Dependence Between the Properties of the Atomic Weights of the Elements." Unfortunately, Mendeleev was ill and the presentation was given by his colleague Professor Menshutken. There were eight points to his presentation:The elements, if arranged according to their atomic weights, exhibit an apparent periodicity of properties.Elements which are similar as regards their chemical properties have atomic weights which are either of nearly the same value (eg. Pt, Ir, Os) or which increase regularly (eg. K, Ru, Cs).The arrangement of the elements, or of groups of elements in the order of their atomic weights, corresponds to their so-called valencies, as well as, to some extent, to their distinctive chemical properties; as is apparent among other series in that of Li, Be, Ba, C, N, O, and Sn.The elements which are the most widely diffused have small atomic weights.The magnitude of the atomic weight determines the character of the element, just as the magnitude of the molecule determines the character of a compound body.We must expect the discovery of many as yet unknown elements-for example, elements analogous to aluminum and silicon- whose atomic weight would be between 65 and 75.The atomic weight of an element may sometimes be amended by a knowledge of those of its contiguous elements. Thus the atomic weight of tellurium must lie between 123 and 126, and cannot be 128.Certain characteristic properties of elements can be foretold from their atomic weights. (18) On November 29, 1870, Mendeleev took his concept even further by stating that it was possible to predict the properties of undiscovered elements. He then proceeded to make predictions for three new elements (eka-aluminum, eka-boron and eka-silicon) and suggested several properties of each, including density, radii, and combining ratios with oxygen, among others. The science world was perplexed, and many scoffed at Mendeleev's predictions. It was not until November, 1875, when the Frenchman Lecoq de Boisbaudran discovered one of the predicted elements (eka-aluminum) which he named Gallium, that Dmitri's ideas were taken seriously. The other two elements were discovered later and their properties were found to be remarkably similar to those predicted by Mendeleev. These discoveries, verifying his predictions and substantiating his law, took him to the top of the science world. He was 35 years old when the initial paper was presentedThroughout the remainder of his life, Dmitri Mendeleev received numerous awards from various organizations including the Davy Medal from the Royal Society of England in 1882, the Copley Medal, the Society's highest award, in 1905, and honorary degrees from universities around the world. Following his resignation from the University of St. Petersburg, the Russian government in 1893 appointed him Director of the Bureau of Weights and Measures. This was believed to have been done to keep down public disapproval of the government. Mendeleev continued to be a popular social figure until his death. In his last lecture at the University of St. Petersburg Mendeleev said:I have achieved an inner freedom. There is nothing in this world that I fear to say. No one nor anything can silence me. This is a good feeling. This is the feeling of a man. I want you to have this feeling too - it is my moral responsibility to help you achieve this inner freedom. I am an evolutionist of a peaceable type. Proceed in a logical and systematic manner. (16) Dmitri Mendeleev was a man who rose out of the crowd to lead his people into the future. The motto of Mendeleev's life was work, which he stated as:Work, look for peace and calm in work: you will find it nowhere else. Pleasures flit by - they are only for yourself; work leaves a mark of long-lasting joy, work is for others. (17) On January 20, 1907 at the age of 73, while listening to a reading of Jules Verne's Journey to the North Pole, (4) Mendeleev floated away, peacefully, for the last time.Bibliography1. D. Abbott, , Ed. "Mendeleev, Dmitri Ivanovich", The Biographical Dictionary of Scientists, Peter Bedrick Books, New York, 1986.2. I. Asimov, Ed. "Mendeleev, Dmitri Ivanovich", Asimov's Biographical Encyclopedia of Science and Technology, 2nd Rev. Ed..,Doubleday, Garden City, NY, 1982.3. R. Clemens, Modern Chemical Discoveries, E.P. Dutton & Co., New York,1956, pp4. B. Harrow, Eminent Chemists of Our Time, 2nd Ed., Van Nostrand, New York,1927, pp ;5. E.J. Holmyard, Makers of Chemistry, Clarendon Press, Oxford, 1929, pp6. A.J. Ihde, The Development of Modern Chemistry, Harper & Row, New York, 1964, pp7. B. Jaffe, Crucibles: The Story of Chemistry, Dover, New York, 1930, pp8. G.B. Kauffman, "Mendeleev, Dimitry Ivanovich", The Electronic Encyclopedia, Grolier, New York, 1988.9. J. Kendall, Young Chemists and Great Discoveries, Appleton-Century, New York, 1939, pp10. H.M. Leicester, The Historical Background of Chemistry, Dover, New York, 1956, pp11. H.M. Leicester, "Dmitrii Ivanovich Mendeleev", in E. Farber, ed., Great Chemists., Interscience, New York, 1961.12. E.G. Mazurs, Graphic Representations of the Periodic System During One Hundred Years, Univ. Alabama Press, University, Alabama, 1975.13. D. Mendeleeff, The Principles of Chemistry, 3rd English Ed., Longmans, Green, and Co., London, 1905.14. J.R. Partington, A History of Chemistry, Vol. 4, Macmillan & Co., London, 1964, pp15. M.M. Pattison Muir, A History of Chemical Theories and Laws, Arno Press, New York, 1975, pp16. D.Q. Posin, Mendeleev, The Story of a Great Chemist, Whittlesey House, New York, 1948.17. T.R. Seshadri, "Mendeleev-as Teacher and Patriot", in T.R. Sheshadri, , ed., Mendeleev's Periodic Classification of Elements and Its Applications, Proceedings of the Symposium held at IIT Kharagpur to celebrate the centenary of Mendeleev's Periodic Classification, Hindustan Pub. Co., Delhi , India, 1973.18. T.E. Thorpe, "Scientific Worthies XXVI. Dmitri Ivanowitsh Mendeleeff", Nature , 1889, XL,19. W.A. Tilden, Famous Chemists, The Men and their Work, Books for Libraries, Freeport, New York, 1921 (rep. 1968) pp20. S.E. Vides Lemus, Clasificacion Periodica de Mendelejew, Editorial del Ministerio de Educacion Publica, Guatemala, 1959, pp"...if all the elements be arranged in order of their atomic weights a periodic repetition of properties is obtained." Mendeleyev
32 Dmitri Mendeleev Russian Invented periodic table Organized elements by propertiesArranged elements by atomic massPredicted existence of several unknown elementsElement 101Dmitri Ivanovich Mendeleev (1834 – 1907)Arranged elements by increasing atomic mass. Proposed that properties of different elements repeat at regular intervals.1860’s proposed new arrangements of elements.1869 Published original periodic tableDmitri Mendeleev was the Russian chemist who invented the periodic table of the elements.He was born in Siberia and was the youngest of 17 children.Mendeleev missed receiving the Nobel prize in chemistry by just one vote in 1906, and died before the next year’s election.Element 101 (discovered in 1955) was named Mendelevium in his honor.Dmitri Mendeleev
33 Dmitri MendeléevIn 1869 Mendeléev published the first effective version of the periodic table of the elements. Unknown to Mendeléev, five years earlier John Newlands had proposed a similar table based on strictly increasing atomic masses forming periods of eight elements. Mendeléev's table used valences as well as atomic masses, enabling him to recognize periods of 18 elements later in the table. Mendeléev was bold in predicting three new elements and their properties for his 1871 version of the table and in rearranging the order from that of atomic masses where needed to make properties fall in line. The three predicted elements were found by 1885, exactly as described, and the rearrangements were justified in 1913 by the discovery of atomic number.The Periodic Table of Elements by Anthony Carpi, Ph.D.In 1869, the Russian chemist Dmitri Mendeleev first proposed that the chemical elements exhibited a "periodicity of properties." Mendeleev had tried to organize the chemical elements according to their atomic weights, assuming that the properties of the elements would gradually change as atomic weight increased. What he found, however, was that the chemical and physical properties of the elements increased gradually and then suddenly changed at distinct steps, or periods. To account for these repeating trends, Mendeleev grouped the elements in a table that had both rows and columns. The modern periodic table of elements is based on Mendeleev's observations; however, instead of being organized by atomic weight, the modern table is arranged by atomic number (Z). As one moves from left to right in a row of the periodic table, the properties of the elements gradually change. At the end of each row, a drastic shift occurs in chemical properties. The next element in order of atomic number is more similar (chemically speaking) to the first element in the row above it; thus a new row begins on the table. For example, oxygen (O), fluorine (F), and neon (Ne) (Z = 8, 9 and 10, respectively) all are stable nonmetals that are gases at room temperature. Sodium (Na, Z = 11), however, is a silver metal that is solid at room temperature, much like the element lithium (Z = 3). Thus sodium begins a new row in the periodic table and is placed directly beneath lithium, highlighting their chemical similarities. Rows in the periodic table are called periods. As one moves from left to right in a given period, the chemical properties of the elements slowly change. Columns in the periodic table are called groups. Elements in a given group in the periodic table share many similar chemical and physical properties.
34 Mendeleev’s Periodic Table 1Group IIIIIIIVVVIVIIVIIIH = 12Li = 7Be= 9.4B = 11C = 12N = 14O = 16F = 193Na = 23Mg = 24Al = 27.3Si = 28P = 31S = 32C = 35.54K = 39Ca = 40? = 44Ti = 48V = 51Cr = 52Mn = 55Fe =56, Co = 59,Ni = 595Cu = 63Zn = 65? = 68? = 72As = 75Se = 78Br = 806Rb = 85Sr = 87? Yt = 88Zr = 90Nb = 94Mo = 96? = 100Ru= 104, Rh = 104, Pd = 1067Ag = 108Cd = 112In = 113Sn = 118Sb = 122Te = 125J = 1278Cs = 133Ba = 137?Di = 138?Ce = 140910?Er = 178?La = 180Ta = 182W = 184Os = 195, Ir = 197,Pt = 19811Au = 199Hg = 200Tl = 204Pb = 207Bi = 20812Th = 231U = 240Dmitri Mendeleyev“To put some order into his study of the known chemical elements, Mendeleyev made up a set of cards, one for each element, listing their chemical properties. He discovered the Periodic Law while arranging these cards. When he put them in order of increasing atomic masses, the properties were repeated periodically.”-Eyewitness Science “Chemistry” , Dr. Ann Newmark, DK Publishing, Inc., 1993, pg 23Mendeleev assumed that all of the elements had not been discovered.He left blanks in his table at atomic masses 44, 68, 72, and 100.When chemical properties of an element suggested that it might have been assigned the wrong place in earlier tables, Mendeleev reexamined its atomic masses and found that some of the atomic masses were incorrect.Noble gases were absent from Mendeleev’s table.William Ramsay discovered the noble gases between 1894 and 1898.
35 Mendeleev’s Early Periodic Table TABELLE IIGRUPPE I GRUPPE II GRUPPE III GRUPPE IV GRUPPE V GRUPPE VI GRUPPE VII GRUPPE VIII___ ___ ___ ___RH RH RH RHR2O RO R2O RO R2O RO R2O RO4REIHEN123456789101112H = 1Li = Be = B = C = N = O = F = 19Na = Mg = Al = Si = P = S = Cl = 35.5?K = Ca = __ = Ti = V = Cr = Mn = Fe = 56, Co = 59,Ni = 59, Cu = 63(Cu = 63) Zn = __ = __ = As = Se = Br = 80Rb = Sr = ? Yt = Zr = Nb = Mo = __ = Ru = 104, Rh = 104,Pd = 106, Ag = 108In the 1860’s, Mendeleev and the German chemist Lothar Meyer, each working alone, made an eight-column table of the elements.However, Mendeleev had to leave some blank spots in order to group all the elements with similar properties in the same column. To explain these blank spots, Mendeleev suggested there must be other elements that had not yet been discovered. On the basis of his arrangement, Mendeleev predicted the properties and atomic masses of several elements that were unknown at the time.Mendeleev left blanks in his table for undiscovered elements.Mendeleev predicted properties and masses of unknown elements correctly.(Ag = 108) Cd = In = Sn = Sb = Te = J = 127Cs = Ba = ? Di = ? Ce = __ __ __ __ __ __ __( __ ) __ __ __ __ __ ____ __ ? Er = ? La = Ta = W = __ Os = 195, Ir = 197,Pt = 198, Au = 199(Au = 199) Hg = Tl= Pb = Bi = __ ____ __ __ Th = __ U = __ __ __ __ __From Annalen der Chemie und Pharmacie, VIII, Supplementary Volume for 1872, p. 151.
36 Elements Properties are Predicted PropertyMendeleev’s Predictions in 1871Observed PropertiesMolar MassOxide formulaDensity of oxideSolubility of oxideScandium (Discovered in 1877)44 gM2O33.5 g / mlDissolves in acids43.7 gSc2O33.86 g / mlMolar massDensity of metalMelting temperatureGallium (Discovered in 1875)68 g6.0 g / mlLowDissolves in ammonia solution69.4 g5.96 g / ml30 0CGa2O3Dissolves in ammoniaColor of metalChloride formulaDensity of chlorideBoiling temperatureof chlorideGermanium (Discovered in 1886)72 g5.5 g / mlDark grayHighMO24.7 g / mlMCl41.9 g / mlBelow 100 oC71.9 g5.47 g / mlGrayish, white900 0CGeO24.70 g / mlGeCl41.89 g / ml86 0CFitting in New Elements“The crowning achievement of Mendeleyev’s periodic table lay in his prophecy of new elements. Gallium, germanium, and scandium were unknown in 1871, but Mendeleyev left spaces for them and even predicted what the atomic masses and other chemical properties would be. The first of these to be discovered in 1875, was gallium. All the characteristics fitted those he had predicted for the elements Mendeleyev called eka-aluminum – because it came below aluminum in his table.”-Eyewitness Science “Chemistry” , Dr. Ann Newmark, DK Publishing, Inc., 1993, pg 23In the 1860’s, Mendeleev and the German chemist Lothar Meyer, each working alone, made an eight-column table of the elements.However, Mendeleev had to leave some blank spots in order to group all the elements with similar properties in the same column. To explain these blank spots, Mendeleev suggested there must be other elements that had not yet been discovered. On the basis of his arrangement, Mendeleev predicted the properties and atomic masses of several elements that were unknown at the time.Mendeleev left blanks in his table for undiscovered elements.Mendeleev predicted properties and masses of unknown elements correctly.O’Connor Davis, MacNab, McClellan, CHEMISTRY Experiments and Principles 1982, page 119,
37 Modern Periodic Table Objective: To explain the modern periodic law concept proposed by Moseley.
38 Periodic Table of the Elements 1He21Li3Be4B5C6N7O8F9Ne102Na11Mg12Al13Si14P15S16Cl17Ar183K19Ca20Sc21Ti22V23Cr24Mn25Fe26Co27Ni28Cu29Zn30Ga31Ge32As33Se34Br35Kr364Rb37Sr38Y39Zr40Nb41Mo42Tc43Ru44Rh45Pd46Ag47Cd48In49Sn50Sb51Te52I53Xe545Cs55Ba56Hf72Ta73W74Re75Os76Ir77Pt78Au79Hg80Tl81Pb82Bi83Po84At85Rn866*Fr87Ra88Rf104Db105Sg106Bh107Hs108Mt1097WLa57Ce58Pr59Nd60Pm61Sm62Eu63Gd64Tb65Dy66Ho67Er68Tm69Yb70Lu71Ac89Th90Pa91U92Np93Pu94Am95Cm96Bk97Cf98Es99Fm100Md101No102Lr103
39 Modern Periodic Table Henry G.J. Moseley Determined the atomic numbers of elements from their X-ray spectra (1914)Arranged elements by increasing atomic numberKilled in WW I at age 28(Battle of Gallipoli in Turkey)H.G.J. Moseley ( ) while doing post-doctoral work (with Ernest Rutherford) bombarded X-rays at atoms in increasing number and noted that the nuclear charge increased by 1 for each element. This gave him the idea to organize the elements by increasing atomic number.Periodic law – elements organized by increasing atomic number on periodic table (1913)In 1913, Moseley analyzed the frequencies of X -rays emitted by the elements and discovered that the underlying foundation of the order of the elements was atomic number, not atomic mass.Moseley hypothesized that the placement of each element in his series corresponded to its atomic number Z, which is the number of positive charges (protons) in its nucleus.Moseley- wavelengths in X-rays determined by the number of protons in the nucleus of the anode atoms- change anode, change wavelength
40 Introduction to the Periodic Table Elements are arranged in seven horizontal rows, in order of increasing atomic number from left to right and from top to bottom.Rows are called periods and are numbered from 1 to 7.Elements with similar chemical properties form vertical columns, called groups, which are numbered from 1 to 18.Groups 1, 2, and 13 through 18 are the main group elements.Groups 3 through 12 are in the middle of the periodic table and are the transition elements.The two rows of 14 elements at the bottom of the periodic are the lanthanides and actinides.Copyright 2007 Pearson Benjamin Cummings. All rights reserved.
41 Groups of Elements Objectives: To apply the following terms to the periodic table of elements:(a) groups (families) and periods (series)(b) representative elements and transition elements(c) metals, semimetals (metalloids), and nonmetals(d) alkali metals, alkaline earth metals, halogens, and noble gases(e) lanthanide series and actinide series(f) rare earth elements and transuranium elementsTo designate a group of elements in the periodic table using both the American convention (IA-VIIIA) and the IUPAC convention (1-18)
43 Groups of Elements 1A 8A H He 2A 3A 4A 5A 6A 7A Li Be B C N O F Ne Na Alkali metals5ANitrogen groupH12AAlkali earth metals6AOxygen groupHe2112ATransition metals7AHalogens3A4A5A6A7A3ABoron group8ANoble gasesLi3Be4B5C6N7O8F9Ne10224ACarbon groupHydrogenInner transition metalsNa11Mg12Al13Si14P15S16Cl17Ar18338B3B4B5B6B7B1B2BK19Ca20Sc21Ti22V23Cr24Mn25Fe26Co27Ni28Cu29Zn30Ga31Ge32As33Se34Br35Kr3644Rb37Sr38Y39Zr40Nb41Mo42Tc43Ru44Rh45Pd46Ag47Cd48In49Sn50Sb51Te52I53Xe5455Cs55Ba56Hf72Ta73W74Re75Os76Ir77Pt78Au79Hg80Tl81Pb82Bi83Po84At85Rn8666**Fr87Ra88Rf104Db105Sg106Bh107Hs108Mt10977WWLa57Ce58Pr59Nd60Pm61Sm62Eu63Gd64Tb65Dy66Ho67Er68Tm69Yb70Lu71*Ac89Th90Pa91U92Np93Pu94Am95Cm96Bk97Cf98Es99Fm100Md101No102Lr103W
44 Groups of Elements 1 18 He Ne Ar Kr Xe Rn 2 13 14 15 16 17 Li Na K Rb 10Ar18Kr36Xe54Rn8621314151617Li3Na11K19Rb37Cs55Fr87Be4Ca20Sr38Ba56Ra88Mg12N7P15As33Sb51Bi83O8S16Se34Te52Po84F9Cl17Br35I53At85The Noble GasesAt the start of the 1890s, no one had any idea that there was a separate group of gases in the periodic table, the noble gases. Noble gases are familiar to us from their use in neon signs and helium balloons. By 1900 this whole new group had been identified and isolated. While trying to determine an accurate atomic mass for nitrogen, British physicist Lord Raleigh ( ) discovered that nitrogen prepared from ammonia was noticeably lighter than nitrogen that came from the atmosphere. He and William Ramsay ( ) both studied “atmospheric” nitrogen. By removing the nitrogen from it, they produced a tiny quantity of another gas. Since it did not react with anything they called it argon, from the Greek word for lazy. The discovery of helium followed a year later in Ramsay and his assistant Morris Travers ( ) then started to search for additional elements in this new group. They attempted this by fractional distillation of large quantities of liquid air and argon. In 1898, their efforts were rewarded; they had prepared krypton, neon, and xenon.Eyewitness Science “Chemistry” , Dr. Ann Newmark, DK Publishing, Inc., 1993, pg 321Alkali metals16Oxygen family2Alkaline earth metals17Halogens15Nitrogen family18Noble gasesDorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 367
45 Diatomic Elements H2 He Li Be B C N2 O2 F2 Ne Na Mg Al Si P S S Cl2 Ar KCaScTiVCrMnFeCoNiCuZnGaGeAsSeBr2KrRbSrYZrNbMoTcRuRhPdAgCdInSnSbTeI2XeCsBaLaHfTaWReOsIrPtAuHgTlTlPbBiPoAtRnFrRaAcCePrNdPmSmEuGdTbDyHoErTmYbLuThPaUNpPuAmCmBkCfEsFmMdNoLr
46 Chemistry of the Groups Elements with similar chemical behavior are in the same group.Elements of Group 1 areElements of Group 2 are theElements of Group 17 are theElements of Group 18 are thealkali metalsalkaline earthshalogensnoble gasesCopyright 2007 Pearson Benjamin Cummings. All rights reserved.
47 Alkali Metals, Group 1 H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K CaScTiVCrMnFeCoNiCuZnGaGeAsSeBrKrRbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXeCsBaLaHfTaWReOsIrPtAuHgTlPbBiPoAtRnFrRaAcCePrNdPmSmEuGdTbDyHoErTmYbLuThPaUNpPuAmCmBkCfEsFmMdNoLr
48 Chemistry of the Groups The alkali metals (Group 1)- The alkali metals are lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr).- Hydrogen is placed in Group 1 but is not a metal.- The alkali metals react readily with nonmetals to give ions with a +1 charge.- Compounds of alkali metals are common in nature and daily life.1H1Li3Na11K19Rb37Cs55Fr87Group 1, the alkali metals– Elements are hydrogen, lithium, sodium, potassium, rubidium, and cesium; the heaviest element (francium) is radioactive– Become less reactive with air or water as their atomic numbers decrease– Alkali metals have ns1 valence-electron configurations and the lowest electronegativity of any group– Have a strong tendency to lose their single electron valence electron to form compounds in the +1 oxidation state, producing the EX monohalides and the E2O oxides– Very reactive and are powerful reducing agents– Used in lithium batteries and cardiac pacemakers; are important industrial chemicals and are important in biologyCopyright 2007 Pearson Benjamin Cummings. All rights reserved.
49 Alkaline Earth Metals, Group 2 HeLiBeBCNOFNeNaMgAlSiPSClArKCaScTiVCrMnFeCoNiCuZnGaGeAsSeBrKrRbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXeCsBaLaHfTaWReOsIrPtAuHgTlPbBiPoAtRnFrRaAcCePrNdPmSmEuGdTbDyHoErTmYbLuThPaUNpPuAmCmBkCfEsFmMdNoLr
50 Chemistry of the Groups The alkaline earths (Group 2)- The alkaline earths are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).- All are metals that react readily with nonmetals to give ions with a 2 charge.2Be4Ca20Sr38Ba56Ra88Mg12Group 2, the alkaline earth metals– Consist of beryllium, magnesium, calcium, strontium, and barium; the heaviest element, radium, is radioactive– Beryllium is relatively unreactive but forms many covalent compounds whereas the other group members are much more reactive metals and form ionic compounds– All alkaline earth elements have ns2 valence-electron configurations– All have low electronegativities– Behave chemically as metals and lose two valence electrons to form compounds in the +2 oxidation state– Are commercially important and are important biologicallyCopyright 2007 Pearson Benjamin Cummings. All rights reserved.
51 Halogens, Group 17 H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca TiVCrMnFeCoNiCuZnGaGeAsSeBrKrRbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXeCsBaLaHfTaWReOsIrPtAuHgTlPbBiPoAtRnFrRaAcCePrNdPmSmEuGdTbDyHoErTmYbLuThPaUNpPuAmCmBkCfEsFmMdNoLr
52 Chemistry of the Groups The halogens (Group 17)- The halogens are fluorine (F), chlorine (Cl), bromine (Br) iodine (), and astatine (At).- They react readily with metals to form ions with a 1 charge.17F9Cl17Br35I53At85Element At. Mass Normal Form at STP b.p., oCFluorine F F2 pale-yellow gasGroup 17, the Halogens– The halogens are fluorine, chlorine, bromine, iodine, and astatine.– All halogens have an ns2np5 valence-electron configuration.– All but astatine are diatomic molecules in which the two halogen atoms share a pair of electrons.– They were not isolated until the eighteenth and nineteenth centuries.– Halogens are nonmetallic and react by gaining one electron per atom to attain a noble gas electron configuration and an oxidation state of –1.– They have high electronegativities.– Elemental fluorine is the most reactive of the halogens and iodine the least.– Halides are produced according to the following equation, in which X denotes a halogen:E + n X2 EXn2– If the element E has a low electronegativity, the product is an ionic halide, nonvolatile substances with high melting points.– If the element E is highly electronegative, the product is a covalent halide, volatile substances with low melting points.– Halogens react with hydrogen to form the hydrogen halides (HX):H2(g) + X2 (g, l, s) 2HX (g)– Fluorine, the most electronegative element, never has a positive oxidation state in any compound.– Other halogens (Cl, Br, ) form compounds in which their oxidation states are +1, +3, +5, and +7, as in the oxoanions (XO-n), where n = 1-4– All of the halogens except astatine (radioactive) are commercially important.Chlorine Cl Cl2 greenish-yellow gasBromine Br Br2 red-brown liquidIodine I I2 black solid (m.p.113oC)Astatine At (210)Copyright 2007 Pearson Benjamin Cummings. All rights reserved.
53 Noble Gases, Group 18 H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K CaScTiVCrMnFeCoNiCuZnGaGeAsSeBrKrRbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXeCsBaLaHfTaWReOsIrPtAuHgTlPbBiPoAtRnFrRaAcCePrNdPmSmEuGdTbDyHoErTmYbLuThPaUNpPuAmCmBkCfEsFmMdNoLr
55 Chalcogens, Group 16 H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K CaScTiVCrMnFeCoNiCuZnGaGeAsSeBrKrRbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXeCsBaLaHfTaWReOsIrPtAuHgTlPbBiPoAtRnFrRaAcCePrNdPmSmEuGdTbDyHoErTmYbLuThPaUNpPuAmCmBkCfEsFmMdNoLr
57 Pnicogens, Group 15 H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca TiVCrMnFeCoNiCuZnGaGeAsSeBrKrRbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXeCsBaLaHfTaWReOsIrPtAuHgTlPbBiPoAtRnFrRaAcCePrNdPmSmEuGdTbDyHoErTmYbLuThPaUNpPuAmCmBkCfEsFmMdNoLr
61 Lanthanide Series H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca TiVCrMnFeCoNiCuZnGaGeAsSeBrKrRbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXeCsBaLaHfTaWReOsIrPtAuHgTlPbBiPoAtRnFrRaAcLaCePrNdPmSmEuGdTbDyHoErTmYbLuThPaUNpPuAmCmBkCfEsFmMdNoLr
62 Actinide Series H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc VCrMnFeCoNiCuZnGaGeAsSeBrKrRbSrYZrNbMoTcRuRhPdAgCdInSnSbTeIXeCsBaLaHfTaWReOsIrPtAuHgTlPbBiPoAtRnFrRaAcLaCePrNdPmSmEuGdTbDyHoErTmYbLuLaThPaUNpPuAmCmBkCfEsFmMdNoLr
63 Chemistry of the Groups 1A8AH1He2112A3A4A5A6A7ALi3Be4Transition MetalsB5C6N7O8F9Ne1022Na11Mg12Al13Si14P15S16Cl17Ar18338B3B4B5B6B7B1B2BK19Ca20Sc21Ti22V23Cr24Mn25Fe26Co27Ni28Cu29Zn30Ga31Ge32As33Se34Br35Kr3644Rb37Sr38Y39Zr40Nb41Mo42Tc43Ru44Rh45Pd46Ag47Cd48In49Sn50Sb51Te52I53Xe5455Cs55Ba56Hf72Ta73W74Re75Os76Ir77Pt78Au79Hg80Tl81Pb82Bi83Po84At85Rn8666**Elements in each column of the d block have vertical similarities in chemical behavior and also display strong horizontal similarities.Horizontal trends compete with vertical trends.Transition metals have multiple oxidation states that are separated by only one electron.Group-6 elements chromium, molybdenum, and tungsten illustrate the competition that occurs between these horizontal and vertical trends — transition metals in Group 6 have different tendencies to achieve their maximum oxidation state.Groups 3 (scandium, lanthanum, actinium), 11 (copper, silver, gold) and 12 (zinc, cadmium, mercury) are the only transition metal groups in which the oxidation state predicted by the valence-electron configuration dominates the chemistry of the group.Transition metals contain partially filled sets of d orbitals and the lanthanides and actinides are those groups in which f orbitals are being filled.These groups exhibit strong horizontal similarities in behavior.Many of the transition metals form M2+ ions.Chemistry of lanthanides and actinides is dominated by M3+ ions.Fr87Ra88Rf104Db105Sg106Bh107Hs108Mt10977WWLa57Ce58Pr59Nd60Pm61Sm62Eu63Gd64Tb65Dy66Ho67Er68Tm69Yb70Lu71Lanthanides*Ac89Th90Pa91U92Np93Pu94Am95Cm96Bk97Cf98Es99Fm100Md101No102Lr103ActinidesW
64 Coloring Activity Coloring Activity Periodic Table (to be colored) CategoriesColoring ActivityPeriodic Table (to be colored) CategoriesKeys
66 METALS Metals and Nonmetals Nonmetals Metalloids H He Li Be B C N O F 1He21Li3Be4B5C6NonmetalsN7O8F9Ne102Na11Mg12Al13Si14P15S16Cl17Ar183K19Ca20Sc21Ti22V23Cr24Mn25Fe26Co27Ni28Cu29Zn30Ga31Ge32As33Se34Br35Kr364METALSRb37Sr38Y39Zr40Nb41Mo42Tc43Ru44Rh45Pd46Ag47Cd48In49Sn50Sb51Te52I53Xe545MetalloidsCs55Ba56Hf72Ta73W74Re75Os76Ir77Pt78Au79Hg80Tl81Pb82Bi83Po84At85Rn866*Fr87Ra88Rf104Db105Sg106Bh107Hs108Mt1097WLa57Ce58Pr59Nd60Pm61Sm62Eu63Gd64Tb65Dy66Ho67Er68Tm69Yb70Lu71Ac89Th90Pa91U92Np93Pu94Am95Cm96Bk97Cf98Es99Fm100Md101No102Lr103
67 Metals, Nonmetals, & Metalloids 12Nonmetals345Metals67MetalloidsZumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 349
68 Properties of Metals, Nonmetals, and Metalloids malleable, lustrous, ductile, good conductors of heat and electricityNONMETALSgases or brittle solids at room temperature, poorconductors of heat and electricity (insulators)METALLOIDS(Semi-metals)dull, brittle, semi-conductors (used in computer chips)
74 Discovering the Periodic Table NeArKrXePoRnRaEuLuPaAcCSFeCuAgSnAuHgPbAncient TimesCrMnLiKNOFNaBBeHAlSiClCaTiVCoNiSeBrSrYZrNbMoRhPdCdTeIBaTaWOsIrMgCeTbErThUPZnAsSbPtBiMiddTcHfReAtFrPmNpPuAmCmBkCfEsFmMdNoLrHeScGaGeRbRuInCsTlPrNdSmGdDyHoTmYbLaRfDbSgBhHsMt1965-30 elements had been isolated and identifiedknown elementsThe Noble GasesAt the start of the 1890s, no one had any idea that there was a separate group of gases in the periodic table, the noble gases. Noble gases are familiar to us from their use in neon signs and helium balloons. By 1900 this whole new group had been identified and isolated. While trying to determine an accurate atomic mass for nitrogen, British physicist Lord Raleigh ( ) discovered that nitrogen prepared from ammonia was noticeably lighter than nitrogen that came from the atmosphere. He and William Ramsay ( ) both studied “atmospheric” nitrogen. By removing the nitrogen from it, they produced a tiny quantity of another gas. Since it did not react with anything they called it argon, from the Greek word for lazy. The discovery of helium followed a year later in Ramsay and his assistant Morris Travers ( ) then started to search for additional elements in this new group. They attempted this by fractional distillation of large quantities of liquid air and argon. In 1898, their efforts were rewarded; they had prepared krypton, neon, and xenon.Eyewitness Science “Chemistry” , Dr. Ann Newmark, DK Publishing, Inc., 1993, pg 32Timeline of Elements DiscoveryJournal of Chemical Education, Sept. 1989
75 Discovering the Periodic Table NeArKrXePoRnRaEuLuPaAcCSFeCuAgSnAuHgPbAncient TimesCrMnLiKNOFNaBBeHAlSiClCaTiVCoNiSeBrSrYZrNbMoRhPdCdTeIBaTaWOsIrMgCeTbErThUPZnAsSbPtBiMiddTcHfReAtFrPmNpPuAmCmBkCfEsFmMdNoLrHeScGaGeRbRuInCsTlPrNdSmGdDyHoTmYbLaRfDbSgBhHsMt1965-The Noble GasesAt the start of the 1890s, no one had any idea that there was a separate group of gases in the periodic table, the noble gases. Noble gases are familiar to us from their use in neon signs and helium balloons. By 1900 this whole new group had been identified and isolated. While trying to determine an accurate atomic mass for nitrogen, British physicist Lord Raleigh ( ) discovered that nitrogen prepared from ammonia was noticeably lighter than nitrogen that came from the atmosphere. He and William Ramsay ( ) both studied “atmospheric” nitrogen. By removing the nitrogen from it, they produced a tiny quantity of another gas. Since it did not react with anything they called it argon, from the Greek word for lazy. The discovery of helium followed a year later in Ramsay and his assistant Morris Travers ( ) then started to search for additional elements in this new group. They attempted this by fractional distillation of large quantities of liquid air and argon. In 1898, their efforts were rewarded; they had prepared krypton, neon, and xenon.Eyewitness Science “Chemistry” , Dr. Ann Newmark, DK Publishing, Inc., 1993, pg 32Journal of Chemical Education, Sept. 1989
76 Discovering the Periodic Table NeArKrXePoRnRaEuLuPaAcCSFeCuAgSnAuHgPbAncient TimesTcHfReAtFrPmNpPuAmCmBkCfEsFmMdNoLrHeScGaGeRbRuInCsTlPrNdSmGdDyHoTmYbLaCrMnLiKNOFNaBBeHAlSiClCaTiVCoNiSeBrSrYZrNbMoRhPdCdTeIBaTaWOsIrMgCeTbErThUPZnAsSbPtBiMiddRfDbSgBhHsMt1965-The Noble GasesAt the start of the 1890s, no one had any idea that there was a separate group of gases in the periodic table, the noble gases. Noble gases are familiar to us from their use in neon signs and helium balloons. By 1900 this whole new group had been identified and isolated. While trying to determine an accurate atomic mass for nitrogen, British physicist Lord Raleigh ( ) discovered that nitrogen prepared from ammonia was noticeably lighter than nitrogen that came from the atmosphere. He and William Ramsay ( ) both studied “atmospheric” nitrogen. By removing the nitrogen from it, they produced a tiny quantity of another gas. Since it did not react with anything they called it argon, from the Greek word for lazy. The discovery of helium followed a year later in Ramsay and his assistant Morris Travers ( ) then started to search for additional elements in this new group. They attempted this by fractional distillation of large quantities of liquid air and argon. In 1898, their efforts were rewarded; they had prepared krypton, neon, and xenon.Eyewitness Science “Chemistry” , Dr. Ann Newmark, DK Publishing, Inc., 1993, pg 32Journal of Chemical Education, Sept. 1989
77 $ Symbols are Useful c . + - x . The use of symbols is not unique to chemistry.Symbols can be quite helpful - when you know what they mean.ArithmeticMoneyMusic$.c+ - x.“A tidy laboratory means a lazy chemist.” -- Jöns Jacob Berzelius (Swedish chemist, )Image:A Swedish chemist who invented modern chemical symbols.Discovered the elements:silicon, selenium, cerium, and thorium.Jons Jakob Berzelius( )
78 Discovering the Elements Metal gold silver iron mercury tin copper leadSymbolCelestial body Sun Moon Mars Mercury Jupiter Venus SaturnDayLatin (dies) Solie Lunae Martis Mercurii Jovis Veneris SaturniFrench dimanche lundi mardi mercredi jeudi vendredi samediEnglish Sunday Monday Tuesday Wednesday Thursday Friday SaturdayRingnes, Journal of Chemical Education, Sept. 1989, page 731
79 Chemical Symbols Symbols used in the 16th and 17th Century GoldSilverIronCopperLeadTinMercurySunMoonMarsVenusSaturnJupiterMercuryAncient Astronomical SymbolsAlchemical Symbols used in the 15th CenturyFireAirEarthWaterBrownlee, Fuller, Hancock, Sohon, Whitsit, First Principles of Chemistry, 1931, page 74
80 Chemical Symbols Symbols used in the 18th Century AntimonyWaterSulfuric acidCopperSulfurSymbols used by John DaltonCarbonHydrogenOxygenSilverSulfurNitrogenSLeadMercuryCopperCLGoldPotassaSodaGWaterCarbon dioxideAlcoholBrownlee, Fuller, Hancock, Sohon, Whitsit, First Principles of Chemistry, 1931, page 74
81 Origin of Names of Elements Timeline of Elements Discovery
82 Origin of the Names of Elements Title Number of ElementsPre-chemical NamesNames from celestial bodiesNames from mythology / superstition 10Names from minerals / ores,other than geographical names 13Names from colorsNames from properties other than color 8Geographical names from the domicile orworkplace of the discoverer(s) 13Geographical names from minerals / ores 10Constructed namesNames from personsGraphic from:Ringnes, Journal of Chemical Education, Sept. 1989, page 731
83 Origin of the Names of Elements Title Number of ElementsPre-chemical NamesNames from celestial bodiesNames from mythology / superstition 10Names from minerals / ores,other than geographical names 13Names from colorsNames from properties other than color 8Geographical names from the domicile orworkplace of the discoverer(s) 13Geographical names from minerals / ores 10Constructed namesNames from personsGraphic from:Ringnes, Journal of Chemical Education, Sept. 1989, page 731
84 Map of Elements Discovered Ringnes, Journal of Chemical Education, Sept. 1989, page 732
85 Several Synthetic Elements Man-madeBk = BerkeliumCf = CaliforniumAm = AmericiumAll made by nuclear bombardmentat Berkeley, California, U.S.A.
87 Einsteinium (Es) Albert Einstein Relativity E = mc2 Offered Presidency of IsraelElement 99Photoelectric effectSolar calculator
88 Curium (Cm) Madame Curie Pioneer in radioactivity (Ra = radium)25 pounds of pitchblende ore yields 1/1000 of a gram of radiumEmits 2 millions times as much radiation as uranium(Rn = radon gas)Discovered 5 elementsNobel Prize (5 in Curie family)Born in Poland(Po = polonium)MARIE SKLODOWSKA CURIE:Her Life as a Media CompendiumThe following is an account of the life Marie Sklodowska Curie presented as a series of simulated news articles that might have been written during her life time.THE WARSAW TIMESBIRTHS:Maria Sklodowska born, Warsaw, Poland, 7 November, 1867; parents, Wladyslaw and Bronislawa Boguska Sklodowska OBITUARIES:Sophie SklodowskaSophie Skolodowska (1863), eldest daughter of Professor Wladyslaw and Madame Bronislawa Sklodowska died in January,1876 of typhus. She is survived by her parents, three sisters, Bronia, Hela, Maria and one brother Joseph.Bronislawa SkolodowskaBronislaw Skodowska, nee Boguska, succumbed to tuberculosis after a long illness on 9 May,1878. During her lifetime she successfully managed a private boarding school for girls. She is survived by her husband Wladyslaw Sklodowska and her three daughters, Bronia, Hela and Maria and one son, Joseph.LOCAL GIRL GRADUATES WITH TOP HONORSMaria Sklodowska crowned her brilliant high school career by graduating first in her class of She was awarded a gold medal for her outstanding achievements. Maria continues the family tradition of academic excellence. She is the fourth Sklodowska child to receive this great distinction. CLASSIFIED ADVERTISING:Help Wanted: (Maria's First Position)Governess, teacher, disciplinarian, bilinguist for two young girls; position open on 1 January, Inquire: M. Zorawski, Czartoryski Estate, Szezuki, Plock district, Poland.THE PARIS TIMESFEMALE TAKES TOP HONORSAt the graduation ceremonies conducted at the Sorbonne on 28 July, 1894, Maria Sklodowska took second honors in mathematics. Professors Appell and Bouty spoke highly of her gifts and enthusiasm. Professor Lippman has agreed to allow her to work in his laboratory. Only last year did Marie obtain her license in Physics, having ranked first in the graduating class. NUPTIALS:On 26 July, 1895, in Sceaux, France, Marie Sklodowska, daughter of Professor Wladyslaw Sklodowska of Warsaw, Poland became the wife of Pierre Curie, son of Dr.and Mme. Eugene Curie of Sceaux, France in a simple civil ceremony. A reception, held in the garden of the Curie home, immediately followed the ceremony. The couple plan to honeymoon by bicycling in the countryside surrounding Paris. BIRTHS:Irene Curie, born 12 September, 1897; Paris, parents, Pierre and Marie Curie. A FIRST!!!! WOMAN WINS NOBEL PRIZEThe 1903 Nobel Prize for Physics was jointly awarded to Pierre and Marie Sklodowska Curie and Henri Becquerel for the discovery of the two radioactive elements, radium and polonium. The Curies isolated the chloride salts of the elements from uranium-free pitchblende through qualitative analysis and then purified these salts using a series of multiple fractional crystallizations. The presence of these salts were detected using the electrometer, invented by Pierre. Because of the low concentration of these newly discovered elements, it required approximately one ton of the pitchblende to produce 0.1 gram of the salt. Much of the work was done as the subject of Mme. Curie's doctoral thesis in Physics in She coined the term, radioactivity, and named the elements Polonium, after her native country, Poland, and radium for its radiant blue glow. Pierre and Marie's research also included the electric, photographic, luminous, heat, and color effects of radioactivity. Their future goals include plans to isolate and study the properties of the pure metals. BIRTHS:Eve Curie, born 6 December, 1904; Paris , parents, Pierre and Marie Curie. TRAFFIC ACCIDENT CLAIMS LIFE OF NOBEL PRIZE WINNER PIERRE CURIE19 April, 1906: Pierre Curie, who held the Physics chair at the Sorbonne for the past two years, died yesterday as a result of the injuries sustained in a traffic accident. He was struck by a horse-drawn wagon as he walked from his laboratory. He is well known for his discovery of piezoelectricity and for his invention of the electrometer. Most recently, together with his wife and colleague, Marie Curie, and Henri Becquerel, Pierre won the Nobel prize in Physics for their discovery of radioactivity (1903). He is survived by his wife, Marie, two young daughters, Irene and Eve, his father, Dr. Eugene Curie, and one brother, Jacques Curie. MARIE CURIE: FIRST WOMAN LECTURER AT THE SORBONNEMarie Curie has been invited to occupy the Physics chair at the Sorbonne held by her late husband, Pierre Curie, until his recent accidental death. Madame Curie, Nobel prize winner and authority on radioactivity, plans to continue the work she started with her husband. Her inaugural lecture, scheduled for 5 November, 1906 at 1:30 p.m.will explain the theory of ions in gases and her treatise on radioactivity. This will be a unique occurrence in the history of the Sorbonne and only 120 places will be available for students, public and press. MADAME CURIE ISOLATES RADIUM - EARNS SECOND NOBEL PRIZE11 December, 1911, Stockholm, Sweden: For the first time, a person has earned two Nobel prizes. This distinction belongs to a woman, Madame Marie Sklodowska Curie. Professor Curie has already won international acclaim because of her contributions in the discovery of radium and polonium in Her most recent research isolated radium by electrolyzing molten radium chloride. At the negative electrode the radium formed an amalgam with mercury. Heating the amalgam in a silica tube filled with nitrogen at low pressure boiled away the mercury, leaving pure white deposits of radium. Her work at the Sorbonne shows much promise for medical applications. It is interesting to note that this prize was for individual achievements in Chemistry, whereas the 1903 prize was a collaborative effort with her husband, Pierre, and Henri Becquerel in Physics. MARIE CURIE JOINS THE WAR EFFORT1 January, 1915: Nobel laureate, Marie Curie, is using her expertise in science to aid the war efforts in France. With funds from the Union of Women of France, she has converted cars into mobile radiological units. These units, containing portable Roentgen X-ray apparatus and their own dynamo, travel from post to post and are used to help pinpoint the location of shell fragments and bullets in wounds. Due to the efforts of Madame Curie, university laboratories and benefactors have contributed the materials and 150 young women have been selected and trained by her to operate these units. These mobile cars, known as "little curies", and her personal unit, a Renault, are omnipresent on the battlefields. MARIE CURIE RECEIVES GIFT FROM WOMEN OF AMERICA20 May, 1921: Through the efforts of the American journalist, Mrs. William Brown Meloney, the women of America have honored Madame Marie Curie with a gift of one gram of radium. In a specially planned White House ceremony, President Warren G. Harding welcomed Madame Curie and her daughters, Irene and Eve, presenting Marie with the gold key to the case holding the radium. Her sacrifice and tireless efforts throughout the war prompted the women of America to grant the fulfillment of her fondest wish. During her stay in the United states, Madame Curie will also visit prominent academic institutes including Yale, the University of Chicago, Northwestern University, Columbia University and others to receive honorary Doctor of Science degrees, their own acknowledgement of her contributions to science. THE WORLD MOURNS THE DEATH OF A GREAT WOMAN4 July, 1934: Sancellemoz, France. Today the world mourns the death of one of its most prominent scientists. Madame Marie Sklodowska Curie succumbed today to a disease caused by the elusive radium that she devoted her life to discovering and eventually isolating. Her life can be described as a series of paradoxes; she was naturally shy and reserved but because of the magnitude of her discoveries, she was frequently thrown into world limelight. When she and her husband, Pierre, discovered a method of separating radium salts from pitchblende, they shared their method freely, choosing not to patent the process. This decision virtually guaranteed a life of poverty in terms of scientific research for them. Marie's faith in science, her tenacity and her strong work ethic allowed her to pursue and realize her dreams. Her pioneering spirit led the way for the discovery of twenty-nine new radioactive isotopes in the period 1903 to Her work has affected the lives of people everywhere through applications of radioactive principles in medicine, in communication and in industrial technologies. Today, The Radium Institutes in both Warsaw and Paris continue the work Marie and Pierre Curie began. The Curie Institutes stand as living memorials to lives filled with devotion to the pursuit of science. BibliographyEve Curie, Madame Curie, Doubleday, Doran, and Company, Inc., Garden City, N.Y., "Marie Curie", Dictionary of Scientific Biographies , III, Charles C. Gillespie, ed., Charles Scribner's Sons, New York, N.Y., ppRobert Reid, Marie Curie, The American Library, New York, N.Y., 1978.Edward Farber, Nobel Prize Winners in Chemistry , Abelard-Schuman, New York, N.Y., 1963, ppBernard, Jaffe, Crucibles: The Story of Chemistry, Fawcett Publications, Grennwich, Conn., 1967, pp,Aaron J. Ihde, The Development of Modern Chemistry, Dover Publication, Inc., New York, N.Y., 1984, ppMarie Curie (1876–1934)
89 Radium (Ra)Radium was used as a fluorescent paint on watch dials. It wasapplied with thin brushes that workers would lick to keep a fine tip.Many people died from the exposure to radium.
90 Radon Gas Radon gas occurs naturally from the radioactive decay Zone 1 counties have a predicted average indoor radon screeninglevel greater than 4 pCi/L (pico curies per liter) (red zones)Zone 2 counties have a predicted average indoor radon screeninglevel between 2 and 4 pCi/L (orange zones)Zone 3 counties have a predicted average indoor radon screeninglevel less than 2 pCi/L (yellow zones)Radon gas occurs naturallyfrom the radioactive decayof radium. Radium is foundin small amounts in rock.SOURCES OF RADON“Radon, the heaviest noble gas, was first observed as the gas produced by the radioactive element radium when it decayed. Some granites used for building houses have been found to give off tiny amounts of radon, which can accumulate in confined areas.”Eyewitness Science “Chemistry” , Dr. Ann Newmark, DK Publishing, Inc., 1993, pg 33Ra Rn + radiationPredicted fraction of homes over 4 picocuries/liter radon
91 Nobelium (No) Element 102 Inventor: dynamite (TNT) blasting gelatin Nobel Prize Alfred Bernhard Nobel ( ) was born in Stockholm, Sweden on October 31, When he was 9 years old, his family moved to St. Petersburg. He was educated mostly privately and at the age of 16 was a scientifically trained chemist. He loved literature and the natural sciences. He knew English, German, French, Swedish and Russian. He traveled to Paris and USA to continue his studies. Then he worked in his father’s factory. He began to experiment with nitroglycerine, the manufacture of which developed into a world industry. Then he invented new, improved explosive, dynamite. He received a patent in But it isn’t his only discovery. He discovered other explosives, use to mining, constructing highways, railways etc. He traveled a lot, so he wasn’t at home and he was here only on temporary visits. He became very rich. He died on December 10, 1896 in San Remo, Italy and left the major part of his large estate in trust to established five prizes. They are awarded every year in physics, chemistry, psychology or medicine, literature and peace. The distribution of these prizes was begun on December 10, 1901, the fifth anniversary of Nobel’s death. The peace prize is presented in Oslo, other prizes in Stockholm. Two people from Czech republic were awarded the Nobel prizes: Professor Jaroslav Heyrovský in 1959 for the discovery and development of polarography and National Artist Jaroslav Seifert in 1984 for his outstanding contribution to poetry.Image of Alfred Nobel fromTrinitrotolueneAlfred Nobel“Merchant of Death”
92 Seaborgium (Sg) Glenn Seaborg Separated f-block from rest of periodic tableWorked on Manhattan Project(Atomic bomb)Classified until after WW IIElement 106Only living person to have an element named for themGLENN SEABORG: Fizz and FissionOn April 19, 1912 the Seaborgs, a hard working Swedish family in the mining town of Ispeming, Michigan, welcomed a son they named Glenn Theodore. They taught him their family traditions and language from the old country. His father, grandfather, and great-grandfather shared another tradition: they were machinists and that is what Glenn might have been, but his parents decided to move to Southern California when he was ten years old.Seaborg attended high school in the Watts district of Los Angeles where his heritage was one of many ethnic backgrounds. His parents encouraged him to take business courses because the work was cleaner and more reliable than the machinist trade. He chose, however, the college prep courses.In his freshman year, Seaborg decided the textbook was too boring and refused to take a science course. He made the same decision in his sophomore year. In his junior year, he was reminded that if he wanted to go to UCLA he would have to take two years of laboratory science, so he signed up for chemistry. Mr. Reed, his teacher, had a tremendous love for science and built up a great deal of human interest with stories about chemists and chemical discoveries. Seaborg loved chemistry. The next year he took physics and he loved that, too. He thought of majoring in physics in college, but decided on chemistry.When Seaborg started college at UCLA in 1929, the school consisted of only four permanent buildings. To pay his tuition, he worked as a dock laborer, an apricot picker, a lab assistant at a rubber company, and a printer's apprentice. Seaborg's enthusiasm for science grew as he learned of new discoveries in nuclear chemistry and physics which were taking place in Europe and at the nearby Berkeley campus of the University of California. He soon decided to become involved in this emerging science.He earned his degree in chemistry in 1934 and immedaitely went to the University of California at Berkeley, the school of his dreams, to earn his PhD. His background of hard work was an asset as he stayed up all night working the "graveyard shift" in the lead-shielded caveroom using the cyclotron. Here he was involved in the discovery of the elements 93 through 102, a task that required decades of hard work. These elements are today known as neptunium, plutonium, americium, curium, berkelium, californium, einsteinium, fermium, mendelevium, and nobelium. His extensive knowledge of radioactive materials led to his inclusion on the team of scientists who paricipated in the Manhattan Project, the race to produce the atomic bomb.Seaborg worked extensively on the reorganization of the periodic table to show the relationship of the new elements to those already known. His discoveries made the greatest changes in the periodic table since the time of Mendeleev. Because of his extensive knowledge of radioactive elements, in 1961 he was chosen to head the Atomic Energy Commission, a position he held for ten years.Seaborg's achievements led to appearances on radio, television, and in films that were made for teaching. The CHEM Study film, "The Transuranium Elements", shows the chemistry of radioactive elements - the Lanthanides and the Actinides. He wrote several books explaining his work to adults and children. He shared his enthusiasm for discovery with the world and frequently gave credit to the teachers who had helped and inspired him. Even after winning the Nobel Prize in 1951, he was always anxious to retain the connections with his former teachers.Two teachers were especially important to Seaborg. Gilbert N. Lewis introduced him to the idea of valence and bonding and encouraged Seaborg to work hard on his endeavors. Earnest O. Lawrence taught him to use the cyclotron and introduced him to his secretary, Helen Griggs, whom Seaborg later married.Seaborg has been an enthusiastic supporter of education during his entire career. He has helped improve higher education and science and mathematics education at all levels, doing everything from directing research to teaching freshman chemistry. When the Soviet Union launched Sputnick in 1957, Seaborg served as chairman of the steering committee for the CHEM Study curriculum and was on a number of government advisory committees for science and science education. From 1958 to 1961 he was the second Chancellor of the University of California at Berkeley. He has also worked to promote peace between the super powers of the world.On a radio game show, The Quiz Kids, Seaborg was a guest questioner when the host turned the tables and allowed the children to question him. One student asked Seaborg if he had discovered any new elements. Though the announcement was scheduled for the next day, Seaborg answered, " Yes. Recently there have been two new elements discovered, elements with atomic numbers 95 and 96." The program ended with a commercial, making this the first and only time that the announcement of the discovery of new elements was sponsored by Alka-Seltzer.Because of his great concern for education, Seaborg was asked what advice he would give the students. He responded, "If I could tell students anything, it would be two words, 'Work hard'."Bibliography1. J.F. Henahan, "Glenn T. Seaborg -- The Man from Ishpeming", Chemistry, 1978, 51, G.B. Kauffman, "Transuranium Power: Glenn T. Seaborg", Today's Chemist, 1991, 4, 18-24, 32.3. D.W. Ridgway, "Interview with Glenn T. Seaborg", Journal of Chemical Education, 1975, 52,4. G.T. Seaborg, Elements of the Universe, E.P. Dutton, New York, N.Y., 1958.5. G.T. Seaborg, "Modern Alchemy", The Science Teacher,1983, 50,6. G.T. Seaborg, "The Transuranium Elements", Journal of Chemical Education, 1985, 62,Important Films7. G.T. Seaborg, Principal Consultant, Transuranium Elements, CHEM Study Video Series, 1963, updated 1981.8. G.T. Seaborg, Updating the Periodic Table, Discovery Corner, The Lawrence Hall of Science, Audio Graphic Films and Video, Hollywood, CA, 1986.
93 Silicon vs. Silicone Silicon (Si) element Silicone (…Si – O – Si…) polymerSealant (caulk) prevents leaksBreast augmentationNo cause-and-effect relationship exists betweenbreast enlargement and breast cancer. Only oneresearcher found a causal link.
94 Magnesium Mg Atomic Mass 24 amu melting point = 650oC (1202oF) 24.30512MagnesiumAtomic Mass 24 amumelting point = 650oC (1202oF)silver gray metalused in flash bulbs, bombs,and flares8th most abundant element (2.2% of Earth’s crust)lack of Mg produces same biological effectas alcoholism (delirium tremens)FLASH PHOTOGRAPHY“Magnesium metal was produced commercially from the 1860s as wire or ribbon. It readily burns in air, the metal being oxidized to magnesium oxide. The brightness of the white flame made it useful in photography to provide studio lighting.”Eyewitness Science “Chemistry” , Dr. Ann Newmark, DK Publishing, Inc., 1993, pg 40The magnesium fire starter uses magnesium as a flame source of 5400oF.
95 Potassium Metal in Water Newmark, CHEMISTRY, 1993, page 25
96 Electron Filling (orbitals) in Periodic Table Objectives:To predict the highest energy sublevel for an element given its position in the periodic table.To predict the electron configuration for an element given its position in the periodic table.To predict the number of valence electrons for any representative element.To draw the electron dot formula for any representative element.
97 The Periodic Table * * Lanthanides Y Y Actinides Alkaline H He Li Be B NoblegasesAlkalineearth metalsHalogens118H1He221314151617Li3Be4B5C6N7O8F9Ne10Na11Mg123456789101112Al13Si14P15S16Cl17Ar18Transition metalsK19Ca20Sc21Ti22V23Cr24Mn25Fe26Co27Ni28Cu29Zn30Ga31Ge32As33Se34Br35Kr36Alkali metalsRb37Sr38Y39Zr40Nb41Mo42Tc43Ru44Rh45Pd46Ag47Cd48In49Sn50Sb51Te52I53Xe54Cs55Ba56*Hf72Ta73W74Re75Os76Ir77Pt78Au79Hg80Tl81Pb82Bi83Po84At85Rn86Elements with the same valence electron configuration (elements located in the same column of the periodic table) have similar chemistry.Correlation is evident for the elements of Groups 1, 2, 3, 13, 16, 17, and 18.Intervening families in the p block (Groups 14 and 15) straddle the diagonal line separating metals from nonmetals.Noble gases (Group 18) have full valence electron shells.Alkali metals (Group 1) contain only a single electron outside a full shell.Fr87Ra88YRf104Db105Sg106Bh107Hs108Mt109Uun110Uuu111Uub112Uuq113Uuh116Uuo118* LanthanidesLa57Ce58Pr59Nd60Pm61Sm62Eu63Gd64Tb65Dy66Ho67Er68Tm69Yb70Lu71Y ActinidesAc89Th90Pa91U92Np93Pu94Am95Cm96Bk97Cf98Es99Fm100Md101No102Lr103
98 Orbitals Being Filled Groups 1 8 2 1s 1 3 4 5 6 7 1s 2s 2 2p 3 3s 3p 1s2s22p33s3p3d4pPeriods44s4d5p55sBlocks in the periodic table– The periodic table can be divided into “blocks” corresponding to the type of subshell that is being filled.– Two columns on the left are known as the s-block elements and consist of elements in which the ns orbitals are being filled.– Six columns on the right consist of elements in which the np orbitals are being filled and constitute the p block.– In between are the 10 columns of the d block elements in which the (n -1))d orbitals are filled.– At the bottom are the 14 columns of the f block, elements in which the (n - 2)f orbitals are filled.La5d6p66sAc6d77s4fLanthanide series5fActinide seriesZumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 345
99 Electron Filling in Periodic Table ssp12d3456*7Wf*W
100 Electron Filling in Periodic Table metallic character increasesnonmetallic character increasesmetallic character increasesnonmetallic character increases
101 Periodic Table s s H He H p Li Be B C N O F Ne Na Mg d Al Si P S Cl Ar 1He2H1p11Li3Be4B5C6N7O8F9Ne1022Na11Mg12dAl13Si14P15S16Cl17Ar1833K19Ca20Sc21Ti22V23Cr24Mn25Fe26Co27Ni28Cu29Zn30Ga31Ge32As33Se34Br35Kr3644Rb37Sr38Y39Zr40Nb41Mo42Tc43Ru44Rh45Pd46Ag47Cd48In49Sn50Sb51Te52I53Xe5455Cs55Ba56Hf72Ta73W74Re75Os76Ir77Pt78Au79Hg80Tl81Pb82Bi83Po84At85Rn8666**Fr87Ra88Rf104Db105Sg106Bh107Hs108Mt10977WWfLa57Ce58Pr59Nd60Pm61Sm62Eu63Gd64Tb65Dy66Ho67Er68Tm69Yb70Lu71*Ac89Th90Pa91U92Np93Pu94Am95Cm96Bk97Cf98Es99Fm100Md101No102Lr103W
102 Melting Points He H He Mg Symbol Melting point oC Li Be B C N O F Ne 0.126H-259.2He-269.711Mg650SymbolMelting point oCLi180.5Be1283B2027C4100N-210.1O-218.8F-219.6Ne-248.622> 3000 oCoCNa98Mg650Al660Si1423P44.2S119Cl-101Ar-189.633K63.2Ca850Sc1423Ti1677V1917Cr1900Mn1244Fe1539Co1495Ni1455Cu1083Zn420Ga29.78Ge960As817Se217.4Br-7.2Kr-157.244Rb38.8Sr770Y1500Zr1852Nb2487Mo2610Tc2127Ru2427Rh1966Pd1550Ag961Cd321In156.2Sn231.9Sb630.5Te450I113.6Xe-111.955Cs28.6Ba710La920Hf2222Ta2997W3380Re3180Os2727Ir2454Pt1769Au1063Hg-38.9Tl303.6Pb327.4Bi271.3Po254AtRn-7166Ralph A. Burns, Fundamentals of Chemistry , 1999, page 1999
103 Elements with Highest Densities Year DensityElement Discovered (g/cm3)OsmiumIridiumPlatinumRheniumNeptuniumPlutoniumGold prehistoricTungstenUraniumTantalum
104 Densities of Elements H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K 0.071He0.12611Li0.53Be1.8B2.5C2.26N0.81O1.14F1.11Ne1.20422Na0.97Mg1.74Al2.70Si2.4P1.82wS2.07Cl1.557Ar1.40233K0.86Ca1.55Sc(2.5)Ti4.5V5.96Cr7.1Mn7.4Fe7.86Co8.9Ni8.90Cu8.92Zn7.14Ga5.91Ge5.36As5,7Se4.7Br3.119Kr2.644Rb1.53Sr2.6Y5.51Zr6.4Nb8.4Mo10.2Tc11.5Ru12.5Rh12.5Pd12.0Ag10.5Cd8.6In7.3Sn7.3Sb6.7Te6.1I4.93Xe3.0655Cs1.90Ba3.5La6.7Hf13.1Ta16.6W19.3Re21.4Os22.48Ir22.4Pt21.45Au19.3Hg13.55Tl11.85Pb11.34Bi9.8Po9.4At---Rn4.466Element Year Discovered Density (g/cm3)OsmiumIridiumPlatinumRheniumNeptuniumPlutoniumGold prehistoricTungstenUraniumTantalum8.0 – 11.9 g/cm312.0 – 17.9 g/cm3> 18.0 g/cm3Mg1.74SymbolDensity in g/cm3C, for gases, in g/LW
107 H He H Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe 1He2H11Li3Be4B5C6N7O8F9Ne102Na11Mg12Al13Si14P15S16Cl17Ar183K19Ca20Sc21Ti22V23Cr24Mn25Fe26Co27Ni28Cu29Zn30Ga31Ge32As33Se34Br35Kr364Rb37Sr38Y39Zr40Nb41Mo42Tc43Ru44Rh45Pd46Ag47Cd48In49Sn50Sb51Te52I53Xe545Cs55Ba56Hf72Ta73W74Re75Os76Ir77Pt78Au79Hg80Tl81Pb82Bi83Po84At85Rn866*Fr87Ra88Rf104Db105Sg106Bh107Hs108Mt1097WLa57Ce58Pr59Nd60Pm61Sm62Eu63Gd64Tb65Dy66Ho67Er68Tm69Yb70Lu71Ac89Th90Pa91U92Np93Pu94Am95Cm96Bk97Cf98Es99Fm100Md101No102Lr103
108 Electron Filling in Periodic Table ssssH1s1He1s2H1s1pp11Li2s1Be2s2B2p1C2p2N2p3O2p4F2p5Ne2p622Na3s1Mg3s2ddAl3p1Si3p2P3p3S3p4Cl3p5Ar3p633K4s1Ca4s2Sc3d1Ti3d2V3d3Cr3d5Mn3d5Fe3d6Co3d7Ni3d8Cu3d10Zn3d10Ga4p1Ge4p2As4p3Se4p4Br4p5Kr4p644Rb5s1Sr5s2Y4d1Zr4d2Nb4d4Mo4d5Tc4d6Ru4d7Rh4d8Pd4d10Ag4d10Cd4p1In5p1Sn5p2Sb5p3Te5p4I5p5Xe5p655Cs6s1Ba6s2Hf5d2Ta5d3W5d4Re5d5Os5d6Ir5d7Pt5d9Au5d10Hg5d10Tl6p1Pb6p2Bi6p3Po6p4At6p5Rn6p666**by Anthony Carpi, Ph.D.Electron Configuration and the Table The "periodic" nature of chemical properties that Mendeleev had discovered is related to the electron configuration of the atoms of the elements. In other words, the way in which an atom's electrons are arranged around its nucleus affects the properties of the atom.Bohr’s theory of the atom tells us that electrons are not located randomly around an atom's nucleus, but they occur in specific electron shells. Each shell has a limited capacity for electrons. As lower shells are filled, additional electrons reside in more-distant shells.The capacity of the first electron shell is two electrons and for the second shell the capacity is eight. Thus, in our example discussed above, oxygen, with eight protons and eight electrons, carries two electrons in its first shell and six in its second shell. Fluorine, with nine electrons, carries two in its first shell and seven in the second. Neon, with ten electrons, carries two in the first and eight in the second. Because the number of electrons in the second shell increases, we can begin to imagine why the chemical properties gradually change as we move from oxygen to fluorine to neon.Sodium has eleven electrons. Two fit in its first shell, but remember that the second shell can only carry eight electrons. Sodium's eleventh electron cannot fit into either its first or its second shell. This electron takes up residence in yet another orbit, a third electron shell in sodium. The reason that there is a dramatic shift in chemical properties when moving from neon to sodium is because there is a dramatic shift in electron configuration between the two elements. But why is sodium similar to lithium? Let's look at the electron configurations of these elements.Group IA VIA VIIA VIIIA Lithium Oxygen Fluorine NeonSodiumElectron Configurations for Selected ElementsAs you can see in the illustration, while sodium has three electron shells and lithium two, the characteristic they share in common is that they both have only one electron in their outermost electron shell. These outer-shell electrons (called valence electrons) are important in determining the chemical properties of the elements.An element's chemical properties are determined by the way in which its atoms interact with other atoms. If we picture the outer (valence) electron shell of an atom as a sphere encompassing everything inside, then it is only the valence shell that can interact with other atoms - much the same way as it is only the paint on the exterior of your house that "interacts" with, and gets wet by, rain water.An atom's valence shell "covers" inner electron shellsThe valence shell electrons in an atom determine the way it will interact with neighboring atoms, and therefore determine its chemical properties. Since both sodium and lithium have one valence electron, they share similar chemical properties.Electron Configuration Shorthand: For elements in groups labeled A in the periodic table (IA, IIA, etc.), the number of valence electrons corresponds to the group number. Thus Li, Na, and other elements in group IA have one valence electron. Be, Mg, and other group-IIA elements have two valence electrons. B, Al and other group-IIIA elements have three valence electrons, and so on. The row, or period, number that an element resides in on the table is equal to the number of total shells that contain electrons in the atom. H and He in the first period normally have electrons in only the first shell; Li, Be, B, and other period-two elements have two shells occupied, and so on. To write the electron configuration of elements, scientists often use a shorthand in which the element's symbol is followed by the element's electron shells, written as a right-hand parentheses symbol ")". The number of electrons in each shell is then written after the ) symbol. A few examples are shown below.Element Configuration ShorthandHydrogen H )1e-Lithium Li )2e- )1e-Fluorine F )2e- )7e- Na )2e- )8e- )1e- Fr7s1Ra7s2Rf6d2Db6d3Sg6d4Bh6d5Hs6d6Mt6d777WWffLa5d1Ce4f2Pr4f3Nd4f4Pm4f5Sm4f6Eu4f7Gd4f7Tb4f9Dy4f10Ho4f11Er4f12Tm4f13Yb4f14Lu4f114**Ac6d1Th6d2Pa5f2U5f3Np5f4Pu5f6Am5f7Cm5f7Bk5f8Cf5f10Es5f11Fm5f14Md5f13No5f14Lr5f14WW
109 Names and Symbols of Selected Elements Name* Symbol Name* SymbolAluminum Al Lead (plumbum) PbArgon Ar Lithium LiBarium Ba Magnesium MgBoron B Mercury (hydrargyrum) HgBromine Br Neon NeCadmium Cd Nickel NiCalcium Ca Nitrogen NCarbon C Oxygen OChlorine Cl Phosphorus PCobalt Co Potassium (kalium) KCopper (cuprum) Cu Silicon SiFluorine F Silver (argentum) AgGold (aurum) Au Sodium (natrum) NaHelium He Strontium SrHydrogen H Sulfur SIodine I Tin (stannum) SnIron (ferrum) Fe Zinc Zn*Names given in parentheses are ancient Latin or Greek words from which the symbols are derived.
111 Electronegativity The ability of an atom in a molecule to attract sharedelectrons to itself.The Pauling electronegativity scale– Based on measurements of the strengths of covalent bonds between different elements– Pauling arbitrarily set the electronegativity of fluorine at 4.0, thereby creating a scale in which all elements have values between 0 and 4.0– Electronegativities increase diagonally from the lower left to the upper right of the periodic table; elements lying on diagonal lines running from the upper left to lower right tend to have comparable values– Pauling’s method is limited by the fact that many elements do not form stable covalent compounds with other elements– Pauling scale is based on the properties of atoms in moleculesLINUS PAULING A BiographyLinus Pauling was born with twin legacies. Although his parents could give him very little in the way of material wealth, they did give him the better gift of great intelligence. His brilliant mind eventually provided him with financial security as well as his greatest happiness. It can also be argued that this gift of intelligence was responsible for the controversy that seemed to surround everything he did and everything he wrote. He made great intuitive leaps and was frequently criticized for the conclusions he drew from what some felt was too little experimentation, often outside of Pauling's area of expertise. His father was part pharmacist and part "medicine man" and wasn't especially successful at either. At the time when Linus was born in 1901 the family was living in what is now the wealthiest suburb of Portland, Oregon. However, they lived a very precarious existence at the edges of poverty. In fact, when Linus was four, the family moved to his mother's home town of Condon to get financial aid from her family. Condon is a small town in north central Oregon and in many ways then (and now) was a stereotypical 'Western' town with one main street and false fronts on many of the business buildings. In Condon his father took over the town drug store and Linus began exploring the physical world around him. A small creek flows on the south edge of town. There he and a friend explored the rocky creek bed and collected some of the minerals for which Pauling would eventually establish structures at the California Institute of Technology . It was likely during this time in Condon that Pauling developed his antipathy to snow and very cold weather. Condon's altitude is about 4000 feet and during the winter the temperature may not go above -20 Fahrenheit for days at a time. The wind roars through town because the town sits on top of the Columbia Basalt plateau and for miles around there is nothing to deflect the winds.The Pauling family moved back to Portland just after Linus began school. When he was nine, his father died, leaving Linus, his two younger sisters and their mother to make their own way in the world. This began a stretch of more than 15 years when Pauling tried to pursue his education, while his mother tried to get him to quit school and become the support of the family. He did not quit school. However, he did find many ingenious ways to make money and most of it went to help support his mother and sisters. By the time he was twelve he was a freshman at Washington High School in Portland. After four years of learning, with or without the help of his teachers, and of odd jobs (delivering milk, running film projectors, and even working in a shipyard, for example) he left high school. He did not graduate because the high school required their students to take a class in civics and Pauling saw no reason why he should since he could absorb any of that from his own reading. Later, after his Nobel Prize for Peace in 1962, the administration agreed that he had learned civics on his own by granting him his high school diploma. In the fall of 1917 Pauling enrolled in Oregon Agricultural College-now Oregon State University-in Corvallis, Oregon. He sailed through the freshman courses required of a chemical engineering major in spite of the fact that he was also working one hundred hours a month. He was not only supporting himself, but also providing the bulk of his family¹s support. This became more and more arduous after his mother became ill. In fact, he did not return to the college after his sophomore year because of the need for money. However, at the first of November of what would have been his junior year, he received an offer to become an instructor of quantitative analysis at Oregon Agricultural College, a course he had just taken as a sophomore! The offer included a salary of $100 a month and he gladly took it. He himself did not take any courses that year. He met his future wife, Ava Helen Miller, when she was a student in his quantitative analysis class.When he had graduated with his degree in chemical engineering, his mother again began pressuring him to stop his education and make money, perhaps become a secondary school teacher. Pauling, however, had applied to graduate schools at Harvard, Berkeley and the fairly new California Institute of Technology. His first choice was Berkeley because G.N. Lewis himself was the chair of the chemistry department, but Berkeley was too slow in replying to his application. Harvard didn't really interest him much, so his decision was made in favor of Cal. Tech. One year after begining work at Cal. Tech. he married Ava Helen Miller.At the California Institute of Technology his advisor was Roscoe Dickinson, whose area of expertise was X-ray crystallography. At this time Dickinson was investigating the crystal structure of various minerals. In his work with Dickinson, Pauling displayed what was to become his standard method of attacking a problem. According to Dr. Edward Hughes, "He would guess what the structure might be like, and then he would arrange it to fit into the other data. . . he could then calculate the intensities he would get from that structure and then compare it with the observed ones." For the rest of his career Pauling was criticized for using too large an amount of intuition in his work and not always having complete data to back up what he wrote. As well as doing his research work, Pauling was taking courses and serving as a teaching assistant in the freshman chemistry course. He received his Ph. D. in chemistry with high honors in the June of His dissertation comprized the various papers he had already published on the crystal structure of different minerals.A year later, when he was 25, he received a Guggenheim fellowship to study at the University of Munich under Arnold Sommerfeld, a theoretical physicist. Here he began work with quantum mechanics. In January of 1927 he published "The Theoretical Prediction of the Physical Properties of Many Electron Atoms and Ions; Mole Refraction, Diamagnetic Susceptibility, and Extension in Space" in which he applied the concept of quantum mechanics to chemical bonding. In March, a heated exchange took place between Pauling and W.L. Bragg in London over this paper. Bragg believed that Pauling had used some of his ideas without giving him credit for them. According to Pauling, the ideas originated in a paper by Gregor Wentzel on quantum mechanical calculations for electrons in complex atoms. "Wentzel reported poor agreement between the calculated and experimental values, but I found that his calculation was incomplete and that when it was carried out correctly, it led to values... in good agreement with the experimental values." In 1928 he published six principles to decide the structure of complicated crystals. This bothered Bragg even more since they did not all originate with Pauling. Actually, according to Horach Judson, "Pauling clarified them, codified them, demonstrated their generality and power." However, Bragg was spreading stories in England about Pauling's "thievery" and lack of professional ethics.At this time Pauling took an assistant professorship in chemistry at Cal. Tech. There was a discrepancy, however, in what he thought he was being offered and what he was actually given. He had thought he was taking an appointment as Assistant Professor of Theoretical Chemistry and Mathematical Physics. This misunderstanding seems to have been a thorn in his side. However, thorn or no thorn, he began a period of intense and productive work. In 1928 he published a paper on orbital hybridization and resonance. In 1931 he published the first paper, "The Nature of the Chemical Bond". At this time he was also teaching classes. One of his responsibilities was the freshman chemistry course. Richard Noyes, now professor emeritus of physical chemistry at the University of Oregon, remembers that Pauling was an exciting lecturer and had an unbelievable ability as a demonstrator. He would be explaining something and "suddenly his mind would go off in a new direction, frequently into areas where the freshmen couldn't follow him." Dr. Noyes remembers one redox titration when Pauling turned on the buret then stepped to the chalkboard and began to write the equation for the reaction. He was glancing at the flask in which the reaction was taking place and suddenly moved back to the buret and turned it off, then swirled the mixture in the flask. The color was perfect, a perfect endpoint!In 1931 Pauling was awarded the Langmuir Prize of the American Chemical Society for "the most noteworthy work in pure science done by a man under 30 years of age." In the same year he was offered a joint full professorship in both chemistry and physics at the Massachusetts Institute Of Technology. He seriously considered the offer but he didn't want to have to brave the Massachusetts' winters. He ended up by accepting the position for one year only. In 1933 he was made a member of the National Academy of Sciences. He was 32, the youngest appointment to this body ever made.Pauling was later to write, "By 1935, I had worked out most of the fundamental problems connected with the chemical bond." and "My serious interest in what is now called molecular biology began about 1935." He began with a look at hemoglobin. He discovered that the hemoglobin in arteries is repelled by a magnet while that in the veins is attracted to a magnet. His answer to this puzzle resulted in a paper on oxygen's binding to hemoglobin in The work on hemoglobin also lead to work on hydrogen-bonding between the polypeptide chains in proteins and another paper that same year on the denaturing of proteins. Also in 1936, he was made chairman of the Division of Chemistry and Chemical Engineering at Cal. Tech. In 1939 he published his most important book, The Nature of the Chemical Bond.His work on hydrogen-bonding in proteins lead him to develop a theory of protein structure. It was generally accepted that proteins were made up of polypeptide chains which were, in turn, made up of long strings of amino acids, bonded end to end. He tried to demonstrate a way of coiling the polypeptide chain in the protein alpha keratin to match the x-rays that crystallographer W.T. Astbury had taken and interpreted, but was unable to fit a model to the data. Working with Corey, he did establish the structures of many small peptides and established that the peptide bond holding amino acids together is planar. In 1939 they formulated a small set of structural conditions for any model of a popypeptide chain.Finally, in 1948, Pauling worked out the alpha helix structure of a polypeptide. He was in Oxford at this time, confined to bed with nephritis and bored with what he had to read. He says, "I took a sheet of paper and sketched the atoms with the bonds between them and then folded the paper to bend one bond at the right angle, what I thought it should be relative to the other, and kept doing this, making a helix, until I could form hydrogen bonds between one turn of the helix and the next turn of the helix, and it only took a few hours doing that to discover the alpha-helix." In 1954 Linus Pauling was given the Nobel Prize for Chemistry for his work on molecular structure, especially proteins.During World War II Pauling worked on various "war" projects as did everyone at Cal. Tech. He chose not to work on the Manhattan Project, however. At the same time his wife was becoming more and more involved in socialist politics. They fought the internment of their Japanese-American gardener and, with the American Civil Liberties Union, the internment of all the Japanese-Americans. He was also becoming more and more worried about the atomic bomb and the radiation it produced. He became involved in the Scientists Movement, a more-or-less nation-wide group of scientists working for safe control of nuclear power. The Movement believed in ³the necessity for all nations to make every effort to cooperate now in setting up an international administration with police powers which can effectively control at least the means of nuclear warfare.² His wife was a member of the Women's International League for Peace and Freedom. In fact, at this time, she was probably more outspoken on the issues of human rights, peace and the banning of nuclear testing than Pauling was. In 1947 President Truman awarded him the presidential Medal of Merit for his work on crystal structure, the nature of the chemical bond, and his efforts to bring about world peace.In November of 1950, he was subpoenaed to appear before the Senate Investigating Committee on Education of the State of California. He testified for over two hours, "mainly about my reasons for objecting to special loyalty oaths involving inquiry into political beliefs." He wrote the next day, "My own political beliefs are well known. I am not a Communist. I have never been a Communist. I have never been involved with the Communist Party. I am a Rooseveltian Democrat." However, he also believed that no governmental body had the right to ask him to answer those same questions under oath. This was during the early days of the McCarthy "witch hunts", which were stronger at the time in California than at most other places. His position upset some of the trustees and some professors at Cal .Tech., who tried to oust him.This was just after Pauling, working with Corey, had used the idea gained from his paper model to work out the structure of many different protein molecules, all of which contained his alpha-helix. His proposed structure was not immediately accepted by the scientific world, however, especially by scientists in England. Therefore, in January of 1952, Pauling requested a passport to attend a meeting in England, specifically to defend his ideas. The passport was denied because granting it "would not be in the best interest of the United States." He applied again and wrote President Eisenhower, asking him to arrange the issuance of the passport since, "I am a loyal citizen of the United States. I have never been guilty of any unpatriotic or criminal act." The answer came back asking him to provide the State Department with some evidence supporting his claims. He sent a statement, made under oath, stating that he was not a communist, never had been a communist, and had never been involved with the Communist Party. The state department replied that his "anti-communist statements were not sufficiently strong" and again denied the passport on the very day he was supposed to leave for the conference. This pattern of Pauling requesting a passport to attend various conferences and the state department denying the application continued for a little over two years. During this time Einstein wrote a letter to the state department supporting Pauling's right to have a passport. He also wrote Pauling telling him, "It is very meritorious of you to fight for the right to travel."In 1953 Pauling published his book, No More War. Again in April of 1954, when he requested a passport, he was denied it. On November 3 of that year, while he was giving a "routine lecture" on hemoglobin at Cornell University, he was called to the telephone to learn that he had just been awarded the Nobel Prize in Chemistry. His first worry was, would he be able to get a passport so he could accept the prize in person? He applied immediately and for weeks he heard nothing. In Washington there were strong voices opposing the granting of the passport. One senator asked, "Are you in the State Department allowing some group of people in some foreign country to determine which Americans get passports?" On November 27, however, barely two weeks before the ceremony in Sweden, his passport did arrive.His years of being unable to get a passport did more than inconvenience him. In 1948 he was already working toward a description of the structure of DNA. By the early 1950's, Rosalind Franklin and others working at Kings College in London had taken some of the sharpest, most detailed photographs of DNA ever. These are what Watson and Crick used in their successful discovery of the DNA double helix. Had Pauling been able to attend the spring 1952 conference he would likely have seen these photographs and might have come to the same conclusion, before Watson and Crick. It is sure that his not seeing them contributed to his proposed structure which had the phosphate groups closely packed inside a single helix with the bases sticking out around the outside.Pauling continued his political activism, particularly his protesting of atomic bomb testing. This culminated in a petition to the United Nations--signed by 11,021 scientists from around the world--calling for an immediate world-wide ban on nuclear testing. Because of this petition he was subpoenaed to appear before the U.S. Senate Internal Security Committee. The committee wanted him to give the names of the petitioning scientists. Under oath, he admitted that he, Barry Commoner, and Edward Condon had initiated the petition, but refused to give any more names. There was much applause from the gallery and, after a while, the committee backed down. Later, during the Kennedy Administration, after Kennedy had decided to go ahead with atmospheric nuclear testing, Pauling sent President Kennedy a telegram asking, ³Are you to give the orders that will cause you to go down in history as one of the most immoral men of all times and one of the greatest enemies of the human race?² Of course, this telegram raised quite a furor. However, the Kennedys still invited him to a White House dinner honoring Nobel Prize winners of the western hemisphere. On the day of the dinner, both Dr. and Mrs. Pauling took part in a demonstration in front of the White House, then left the picket line to go in to dinner. Later that evening, Pauling even danced with Mrs. Kennedy.On October 10, 1962, it was announced that Linus Pauling had been awarded the Nobel Peace Prize for his efforts on behalf of a nuclear test ban treaty. This award was not universally popular. Many newspapers and magazines printed editorials denouncing him, his activism,and his having been given the prize.Since his second Nobel Prize, Dr. Pauling has researched the chemistry of the brain and its effect on mental illness, the cause of sickle-cell anemia and what is happening to the hemoglobin in the red blood cells of people with this disease, and the effects of large doses of vitamin C on both the common cold and some kinds of cancer. He recently published papers on high temperature super conductivity. He has worked at the University of California at San Diego, at Stanford and at the Linus Pauling Institute for Medical Research. He has won many awards in chemistry, including all the major ones. He remains, as he has been all his life, a brilliant man with brilliant ideas. He was once asked by a high school student , "How can I have great ideas?" Pauling's answer was, "The important thing is to have many ideas." He has certainly followed his own advice.References1. A. Serafini, Linus Pauling A Man and His Science, Paragon House, New York, N.Y., A.J. Ihde, The Development of Modern Chemistry, Dover, New York, N.Y., 1984, pp. 543 & 544, p 551.3. J. H. Sturdivant, "The Scientific Work of Linus Pauling", A. Rich & N. Davidson, Structural Chemistry and Molecular Biology, W.H. Freeman and Co., San Francisco, CA, 1968, pp. 16, 18, 19.4. D.C. Hodgkin & D.P. Riley, "Some Ancient History of Protein X-Ray Analysis", A.Rich and N. Davidson, Structural Chemistry and Molecular Biology, W.H. Freeman and Co., San Francisco, Ca.,1968, pp. 7, 8, 16, 18, 19.5. "Pauling, Linus Carl", S.P. Parker, ed., McGraw-Hill Encyclopedia of Chemistry, Volume 9, McGraw-Hill, New York, N.Y., 1982, ppLinus Pauling
112 Electronegativities Period H B P As Se Ru Rh Pd Te Os Ir Pt Au Po At 2.1B2.0PAsSe2.4Ru2.2RhPdTeOsIrPtAuPoAt112A3A4A5A6A7AActinides:Li1.0CaSc1.3SrY1.2Zr1.4HfMgLa1.1AcLanthanides:*yBe1.5AlSi1.8TiV1.6CrMnFeCoNiCu1.9Zn1.7GaGeNbMoTcAgCdInSnSbTaWReHgTlPbBiN3.0O3.5F4.0ClC2.5SBr2.8I22Na0.9K0.8RbCs0.7BaFrRaBelow 1.0333B4B5B6B7B8B1B2BPeriod445566Linus Pauling ( ) awarded Nobel Prize in chemistry in 1954 for his 1939 text, The Nature of the Chemical Bond,and also won the Nobel Peace Prize in 1962 for his fight to control nuclear weapons.The greater the electronegativity of an atom in a molecule, the more strongly it attracts the electrons in a covalent bond.• Elements with high electronegativities tend to acquire electrons in chemical reactions and are found in the upper-right corner of the periodic table.• Elements with low electronegativities tend to lose electrons in chemical reactions and are found in the lower-left corner of the periodic table.7Hill, Petrucci, General Chemistry An Integrated Approach 2nd Edition, page 373
113 Covalent Bonds Polar-Covalent bonds Nonpolar-Covalent bonds Electrons are unequally sharedElectronegativity difference between 0.3 and 1.7Example: H2O (water)O = 3.5difference is 1.4H = 2.1Metals– Elements with a low electronegativity and that have electron affinities that have either positive or small negative values and small ionization potentials– Are good electrical conductors that tend to lose their valence electrons in chemical reactions (they are reductants)Semimetals– Elements with intermediate electronegativities– Elements that have some of the chemical properties of both nonmetals and metalsNonpolar-Covalent bondsElectrons are equally sharedElectronegativity difference of 0 to 0.3
120 Diatomic MoleculesElements That Exist as Diatomic Molecules in Their Elemental FormsElement Present Elemental State at 25 oC Moleculehydrogen colorless gas H2nitrogen colorless gas N2oxygen pale blue gas O2fluorine pale yellow gas F2chlorine pale green gas Cl2bromine reddish-brown liquid Br2iodine lustrous, dark purple solid I2
121 Size of Atoms - Trends Objectives: To state the trend in atomic size within a group or period of elements.To state the trend in metallic character within a group or period.
122 Atomic Radii = 1 Angstrom IA IIA IIIA IVA VA VIA VIIALiBeBCNOFNaMgAlSiPSClKCaGaGeAsSeBrDifficult to measure the dimensions of an individual atomDistances between the nuclei in pairs of covalently bonded atoms can be measured and are used as a basis for describing the approximate sizes of atomsCovalent atomic radius is half the internuclear distance in a molecule that contains two identical atoms bonded to each other, can be determined for most of the nonmetalsFor metals, the metallic atomic radius is defined as half the distance between the nuclei of two adjacent metal atomsFor elements such as the noble gases, most of which form no stable compounds, van der Waals atomic radius is used and is half the internuclear distance between two nonbonded atoms in the solidAtomic size seems to vary in a periodic fashion.• In the periodic table, atomic radii decrease from left to right across a row because of the increase in effective nuclear charge due to poor electron screening by other electrons in the same principal shell. Atomic radii increase from top to bottom down a column because the effective nuclear charge remains constant as the principal quantum number increases.• The largest atoms are found in the lower-left corner of the periodic table and the smallest in the upper-right corner.RbSrInSnSbTeICsBaTlPbBi= 1 Angstrom
123 atomic radius atomic number 0.3 Cs Rb 0.25 K 0.2 Na La Li 0.15 Zn Xe transitionseries4dtransitionseriesatomic radiusLaLi0.15ZnXeKr0.1ClF0.05HeHatomic number
124 Periodic Trends in Atomic Radii LeMay Jr, Beall, Robblee, Brower, Chemistry Connections to Our Changing World , 1996, page 175
125 Relative Size of AtomsZumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 350
126 Attraction and Repulsion of Electrical Charges +-++--Particles with oppositecharges attractone another.Particles with like chargesrepel one another.
127 Coulombic Attraction 1+ 1- A 4- 3- D 2+ 2- B Coulombic Attraction 1) Chargeopposites attractlike repels2) Distance2+2-C
128 + Shielding Effect - - - - nucleus Electron Valence+-nucleus--Electrons-Some schools use the term “screening” as I use the term “shielding”.ElectronShield“kernel”electronsKernel electrons block the attractive force of the nucleus from the valence electrons
129 Shielding Effect and Effective Nuclear Charge Mg24.30512Shielding Effect and Effective Nuclear Chargeattractionsrepulsions+_"The simplified sketch of a magnesium atom shows the two valence electrons as discrete particles.The remaining 9 core electrons are shown as a circular cloud of negative electric charge.Interactions between valence electrons, core electrons, and the atomic nucleus determine aneffective nuclear charge. Attractions are indicated in red and repulsion in blue.“For an atom or ion that has only a single electron, the potential energy can be calculated by considering only the electrostatic attraction between the positively charged nucleus and the negatively charged electron.When more than one electron is present, the total energy of the atom or ion depends not only on the attractive electron-nucleus interactions but also on repulsive electron-electron interactions.One must use approximate methods to deal with the effect of electron-electron repulsions on orbital energiesIf an electron is far from the nucleus, then at any given moment, most of the other electrons will be between that electron and the nucleus.The electrons will cancel a portion of the positive charge of the nucleus and will decrease the attractive interaction between it and the electron farther away.Electrons farther away experiences an effective nuclear charge, Zeff. that is less than the actual nuclear charge Z (an effect called electron shielding).__Mg = [Ne]3s2Hill, Petrucci, General Chemistry An Integrated Approach 2nd Edition, page 336
130 Decreasing Atomic Size Across a Period As the attraction between the (+) nucleus and the (–) valence electrons , the atomic size . Greater coulombic attraction.From left to right, size decreases because there is an increase in nuclear charge and Effective Nuclear Charge (# protons – # core electrons).Each valence electron is pulled by the full ENCLiBeB1s22s11s22s21s22s22p1(ENC = 1)(ENC = 2)(ENC = 3)LiBeB++++++++++++
131 Sizes of ions: electron repulsion Valence electrons repel each other.When an atom becomes a anion (adds an electron to its valence shell) the repulsion between valence electrons increases without changing ENCThus, F– is larger than F9 +.9+-9+-+1e-Fluorine atomF1s22s22p5Fluoride ionFluorine ionF1-1s22s22p6
132 Atomic Radius of AtomsBeBCNOFNaMgAlSiPSClKCaGaGeAsSeBrRbSrInSnSbTeICsBaTlPbBiAtomic size seems to vary in a periodic fashion.• In the periodic table, atomic radii decrease from left to right across a row because of the increase in effective nuclear charge due to poor electron screening by other electrons in the same principal shell. Atomic radii increase from top to bottom down a column because the effective nuclear charge remains constant as the principal quantum number increases.• The largest atoms are found in the lower-left corner of the periodic table and the smallest in the upper-right corner.
133 Atomic Radii Ionic Radii = 1 Angstrom = 1 Angstrom 0.95IA IIA IIIA IVA VA VIA VIIA= 1 AngstromLi1+Be2+Na1+Mg2+Ba2+Sr2+Ca2+K1+Rb1+Cs1+Cl1-N3-O2-F1-S2-Se2-Br1-Te2-I1-Al3+Ga3+In3+Tl3+IA IIA IIIA IVA VA VIA VIIALiNaKRbCsClSPSiAlBrSeAsGeGaITeSbSnInTlPbBiMgCaSrBaBeFONCB= 1 Angstrom
134 Atomic Radii = 1 Angstrom Ar Kr Xe Rn Ne VIIIA He 0.931.121.541.691.902.20LiNaKRbCsClSPSiAlBrSeAsGeGaITeSbSnInTlPbBiMgCaSrBaBeFONCBIA IIA IIIA IVA VA VIA VIIAThe atomic radius increases with atomic number in a particular group or family of elements. Each element in a group has one more shell or energy level than the element above it. Even though the nuclear charge increases and tends to decrease the radii of the electron shells by drawing them closer, the addition of a shell more than counteracts this effect.In a series or period, the atomic radius generally decreases from group 1 to group 7. The noble gas in group 8 has a larger radius, but not as great a one as that of the elements of groups 1 and 2 of the same period. The decrease in atomic radius across a period is due to the greater attraction of the increasing nuclear charge for electrons entering the same shell, thus pulling them closer to the nucleus. The irregularities may be due to the shell-enlarging effect of the mutual repulsion of electrons entering the same subshell. The greater size of the noble gas atoms is due to the structural stability of an outer shell consisting of an octet.
135 Ionic Radii = 1 Angstrom IA IIA IIIA IVA VA VIA VIIA 0.60 0.31 0.95IA IIA IIIA IVA VA VIA VIIA= 1 AngstromLi1+Be2+Na1+Mg2+Ba2+Sr2+Ca2+K1+Rb1+Cs1+Cl1-N3-O2-F1-S2-Se2-Br1-Te2-I1-Al3+Ga3+In3+Tl3+
136 Trends in Atomic and Ionic Size MetalsNonmetalsGroup 1Al14350eGroup 13Group 17ee152186227LiNaK60Li+F-136FClBr6499114ee95Na+Cl-181Al3+ee133K+Br-195Cations are smaller than parent atomsAnions are larger than parent atoms
137 Li Li+ e Energy e Li Lithium atom e Li+ e Li Li + e Lithium ion 152Li60Li+eEnergye152LiLithium atom152e60Li+eLiLi+eLithium ionLithium atom
138 Atomic Radii Ionic Radii IA IIA IIIA IVA VA VIA VIIALiNaKRbCsClSPSiAlBrSeAsGeGaITeSbSnInTlPbBiMgCaSrBaBeBCNOFAtomicRadii0.95Li1+Be2+Na1+Mg2+Cl1-N3-O2-F1-S2-Se2-Br1-Te2-I1-Al3+Ga3+In3+Tl3+Ca2+K1+Sr2+Rb1+Cs1+Ba2+IonicRadii• Trends in atomic size result from differences in the effective nuclear charges experienced by electrons in the outermost orbitals of the elements.• Effective nuclear charge is always less than the actual nuclear charge because of shielding effects.• The greater the effective nuclear charge, the more strongly the outermost electrons are attracted to the nucleus and the smaller the atomic radius.• It is possible to measure the distance between the nuclei of a cation and an adjacent anion in an ionic compound in order to determine the ionic radius of one or both.• Internuclear distance corresponds to the sum of the radii of the cation and anion.• Comparison of ionic radii with atomic radii shows that cations are always smaller than the parent neutral atom, and anions are always larger than the parent neutral atom.• When one or more electrons is removed from a neutral atom, two things happen:1. Repulsions between electrons in the same principal shell decrease because fewer electrons are present.2. The effective nuclear charge felt by the remaining electrons increases because there are fewer electrons to shield one another from the nucleus.Most elements form either a cation or an anion but not both.• There are few opportunities to compare the sizes of a cation and an anion derived from the same neutral atom.• Ionic radii follow the same vertical trend as atomic radii.• For ions with the same charge, the ionic radius increases going down a column due to shielding by filled inner shells, which produces little change in the effective nuclear charge felt by the outermost electrons.• Principal shells with larger values of n lie at successively greater distances from the nucleus.Cations: smallerthan parent atomsAnions: LARGERthan parent atoms= 1 Angstrom
139 The Octet Rule and Common Ions 8+-9+11+12+10+-Oxygen atomO1s22s22p4Fluorine atomF1s22s22p5Neon atomNe1s22s22p6Sodium atomNa1s22s22p63s1Magnesium atomMg1s22s22p63s2+2e-+1e--1e--2e-• Most elements form either a cation or an anion but not both.• There are few opportunities to compare the sizes of a cation and an anion derived from the same neutral atom.• Ionic radii follow the same vertical trend as atomic radii.• For ions with the same charge, the ionic radius increases going down a column due to shielding by filled inner shells, which produces little change in the effective nuclear charge felt by the outermost electrons.• Principal shells with larger values of n lie at successively greater distances from the nucleus.• Elements in different columns tend to form ions with different charges — it is not possible to compare ions of the same charge across a row of the periodic table.• Elements that are next to each other tend to form ions with the same number of electrons but with different overall charges because of their different atomic numbers.• Comparison of the dimensions of atoms or ions that have the same number of electrons but different nuclear charges called an isoelectronic series.• An isoelectronic series shows a clear correlation between increasing nuclear charge and decreasing size.8+-9+-11+-12+-Oxygen ionO2-1s22s22p6Fluorine ionF1-1s22s22p6Sodium ionNa1+1s22s22p6Magnesium ionMg2+1s22s22p6
140 Isoelectronic Species Isoelectronic - all species have the same number of electrons.p = 8n = 8e = 10p = 9n = 9e = 10p = 10n = 10e = 10p = 11n = 11e = 10p = 12n = 12e = 108+-9+-10+-11+-12+-Oxygen ionO2-1s22s22p6Fluorine ionF1-1s22s22p6Neon atomNe1s22s22p6Sodium ionNa1+1s22s22p6Magnesium ionMg2+1s22s22p6• Most elements form either a cation or an anion but not both.• There are few opportunities to compare the sizes of a cation and an anion derived from the same neutral atom.• Ionic radii follow the same vertical trend as atomic radii.• For ions with the same charge, the ionic radius increases going down a column due to shielding by filled inner shells, which produces little change in the effective nuclear charge felt by the outermost electrons.• Principal shells with larger values of n lie at successively greater distances from the nucleus.• Elements in different columns tend to form ions with different charges — it is not possible to compare ions of the same charge across a row of the periodic table.• Elements that are next to each other tend to form ions with the same number of electrons but with different overall charges because of their different atomic numbers.• Comparison of the dimensions of atoms or ions that have the same number of electrons but different nuclear charges called an isoelectronic series.• An isoelectronic series shows a clear correlation between increasing nuclear charge and decreasing size.Can you come up with another isoelectronic series of five elements?
141 Na Cl H C N H C N Na Cl Lewis Structure Na Cl H C N “Lewis Dot Notation”NaClooHCNXDoooDoXDXXDGilbert LewisXDooNaClHCNHCNNaCl
142 Atomic Radius vs. Atomic Number 0.3CsRb0.25K0.2Na3dtransitionseries4dtransitionseriesatomic radiusLaLi0.15ZnXeKr0.1ClF0.05HeHatomic number
143 Ionization Energy Objectives: To state the general trends of ionization energy in the periodic table.To state the group with the highest and the lowest ionization energies.To predict the ionic charge for any representative element.To write the predicted electron configuration for selected ions.
144 Hungry for Tater Tots?Mr. C at 7 years old.Photograph is of me (Mr. Christopherson in 1973, age 7)Story that goes along with this slide is told in class.
145 OUCH!!Atoms tend to lose, gain or share electrons to reach a total of eight valence electrons, called an octet.The octet rule explains the stoichiometry of most compounds in the s and p blocks of the periodic table.Number eight corresponds to one ns and three np valence orbitals, which together can accommodate a total of eight electrons.
146 Ionization Energies Period H He Mg Li Be B C N O F Ne Na Mg Al Si P S Group 118H1312SymbolFirst Ionization Energy(kJ/mol)He237211Mg73821314151617Li520Be900B801C1086N1402O1314F1681Ne208122Na496Mg738Al578Si787P1012S1000Cl1251Ar1521333456789101112PeriodK419Ca590Sc633Ti659V651Cr653Mn717Fe762Co760Ni737Cu746Zn906Ga579Ge762As947Se941Br1140Kr135144Rb403Sr550Y600Zr640Nb652Mo684Tc702Ru710Rh720Pd804Ag731Cd868In558Sn709Sb834Te869I1008Xe117055Cs376Ba503La538*Hf659Ta761W770Re760Os839Ir878Pt868Au890Hg1007Tl589Pb716Bi703Po812At--Rn103866Linus Pauling ( ) awarded Nobel Prize in chemistry in 1954 for his 1939 text, The Nature of the Chemical Bond,and also won the Nobel Peace Prize in 1962 for his fight to control nuclear weapons.The greater the electronegativity of an atom in a molecule, the more strongly it attracts the electrons in a covalent bond.First ionization energies decrease down a column.a. Filled inner shells are effective at screening the valence electrons, so there is a small increase in the effective nuclear charge.b. The atoms become larger as they acquire electrons.c. Valence electrons farther from the nucleus are less tightly bound, making them easier to remove and causing ionization energies to decrease.d. A larger nucleus radius corresponds to a lower ionization energy.Fr--Ra509Ac490yRf--Db--Sg--Bh--Hs--Mt--Ds--Uuu--Uub--Uut--Uuq--Uup--7*Lanthanide seriesCe534Pr527Nd533Pm536Sm545Eu547Gd592Tb566Dy573Ho581Er589Tm597Yb603Lu523yActinide seriesTh587Pa570U598Np600Pu585Am578Cm581Bk601Cf608Es619Fm627Md635No642Lr--
147 First Ionization Energies (in kilojoules per mole) H1312.1He2372.5Li520.3Be899.5B800.7C1086.5N1402.4O1314.0F1681.1Ne2080.8Na495.9Mg737.8Al577.6Si786.5P1011.8S999.7Cl1251.2Ar1520.6Metals have low ionization energy; nonmetals have high ionization energy.This experimental data gives evidence for:1) effect of increasing nuclear charge2) stability of octet3) effect of increased radius4) s & p sublevel in outer levelSUGGESTION: Emphasize that theories came from experimental evidence!K418.9Ca589.9Ga578.6Ge761.2As946.5Se940.7Br1142.7Kr1350.8Rb402.9Sr549.2In558.2Sn708.4Sb833.8Te869.0I1008.7Xe1170.3Smoot, Price, Smith, Chemistry A Modern Course 1987, page 188
148 First Ionization Energies (kJ/mol) pH1312.1He2372.5Li520.3Be899.5B800.7C1086.5N1402.4O1314.0F1681.1Ne2080.8Na495.9Mg737.8Al577.6Si786.5P1011.8S999.7Cl1251.2Ar1520.6Metals have low ionization energy; nonmetals have high ionization energy.This experimental data gives evidence for:1) effect of increasing nuclear charge2) stability of octet3) effect of increased radius4) s & p sublevel in outer levelSUGGESTION: Emphasize that theories came from experimental evidence!K418.9Ca589.9Ga578.6Ge761.2As946.5Se940.7Br1142.7Kr1350.8Rb402.9Sr549.2In558.2Sn708.4Sb833.8Te869.0I1008.7Xe1170.3Smoot, Price, Smith, Chemistry A Modern Course 1987, page 188
149 First Ionization Energies (kJ/mol) MetalMetalloidNonmetalspH1312.1He2372.5Li520.3Be899.5B800.7C1086.5N1402.4O1314.0F1681.1Ne2080.8Na495.9Mg737.8Al577.6Si786.5P1011.8S999.7Cl1251.2Ar1520.6Metals have low ionization energy; nonmetals have high ionization energy.This experimental data gives evidence for:1) effect of increasing nuclear charge2) stability of octet3) effect of increased radius4) s & p sublevel in outer levelSUGGESTION: Emphasize that theories came from experimental evidence!Note: Atoms do not lose d- or f-sublevel electrons.Why? Only valence electrons (s- and p- orbitals) are removed. Kernel electrons (d- and f-orbitals) are not lost.K418.9Ca589.9Ga578.6Ge761.2As946.5Se940.7Br1142.7Kr1350.8Rb402.9Sr549.2In558.2Sn708.4Sb833.8Te869.0I1008.7Xe1170.3Smoot, Price, Smith, Chemistry A Modern Course 1987, page 188
150 First Ionization energy HeHelium (He) has…a greater IE than Hsame shieldinggreater nuclear chargenHFirst Ionization energyHeH1+2+1e-2e-Atomic number
151 First Ionization energy HeLi has…lower IE than Hmore shieldingFurther away outweighs greater nuclear chargenHFirst Ionization energyLiAtomic number
152 First Ionization energy HeBe has higher IE than Lisame shieldinggreater nuclear chargen1e-2e-3+4+H3+4+2e-1e-First Ionization energyBeBeLiLiAtomic number
153 First Ionization energy HeB has lower IE than Besame shieldinggreater nuclear chargep-orbitals availablen2e-4+3e-5+4+5+2e-3e-HFirst Ionization energyBeBBeBLi2s2p1sAtomic number
154 First Ionization energy HenHFirst Ionization energyCBeBLi2s2p1sAtomic number
155 First Ionization energy HenNHFirst Ionization energyCBeBLi2s2p1sAtomic number
156 First Ionization energy HenNBreaks the pattern becauseremoving an electrongets to ½ filled p-orbitalHOFirst Ionization energyCBeBLi2s2p1sAtomic number
157 First Ionization energy HenFNHOFirst Ionization energyCBeBLi2s2p1sAtomic number
158 First Ionization energy HeNenFNNe has a lower IE than HeBoth are full energy levels,Ne has more shieldingGreater distanceHOFirst Ionization energyCBeBLi2s2p1sAtomic number
159 First Ionization energy HHeLiBeBCNOFNeNanNa has a lower IE than LiBoth are s1Na has more shieldingGreater distanceFirst Ionization energy2s2p1s3sAtomic number
160 First Ionization energy HeBe has higher IE than Lisame shieldinggreater nuclear chargenHBeLi3+4+2e-1e-First Ionization energyBeLiAtomic number
161 First Ionization energy HeB has lower IE than Besame shieldinggreater nuclear chargep-orbitals availablenBBe4+5+2e-3e-HFirst Ionization energyBeBLi2s2p1sAtomic number
162 First Ionization energy HHeLiBeBCNOFNeNaNa has a lower IE than LiBoth are s1Na has more shieldingGreater distanceFirst Ionization energyAtomic number
163 First Ionization energy HeNeArKrHLiNaKRbFirst Ionization energyAtomic number
164 First Ionization energy HeNeArKrHLiNaKRbFirst Ionization energyAtomic number
165 First Ionization Energy Plot 2500HeNe2000FAr1500NKrClFirst ionization energy (kJ/mol)HBrOPCZnAs1000BeIonization energies of s- and p-block elements– For elements in the third row of the periodic table, successive ionization energies increase steadily as electrons are removed from the valence orbitals (3s or 3p) followed by a large increase in ionization energy when electrons are removed from filled core levels.– First ionization energies tend to increase across the third row of the periodic table because the valence electrons do not screen each other, allowing the effective nuclear charge to increase steadily across the row.– Valence electrons are attracted more strongly by the nucleus, so atomic sizes decrease and ionization energies increase.– The first ionization energies of the elements in the first six rows of the periodic table illustrate three trends:1. Changes seen in the second, fourth, fifth, and sixth rows of the s and p blocks follow a pattern described for the third row of the periodic table.a. Transition metals are included in the fourth, fifth, and sixth rows.b. Lanthanides are included in the sixth row.c. Ionization energies increase from left to right across each row.2. First ionization energies decrease down a column.a. Filled inner shells are effective at screening the valence electrons, so there is a small increase in the effective nuclear charge.b. The atoms become larger as they acquire electrons.c. Valence electrons farther from the nucleus are less tightly bound, making them easier to remove and causing ionization energies to decrease.d. A larger nucleus radius corresponds to a lower ionization energy.3. Because of the trends described in 1 and 2;a. the elements that form positive ions most easily (have the lowest ionization energies) lie in the lower-left corner of the periodic table;b. those elements that are hardest to ionize lie in the upper-right corner of the periodic table;c. ionization energies increase diagonally from lower left to upper right;d. minor deviations from this trend can be explained in terms of particularly stable electronic configurations, called pseudo-inert gas configurations, in either the parent atom or the resulting ion.• Ionization energies of transition metals and lanthanides– First ionization energies of transition metals and lanthanides change very little across each row.– Differences in their second and third ionization energies are also small.– Transition metals and lanthanides form cations by losing the ns electrons before the (n – 1)d or (n – 2)f electrons.– Because their first, second, and third ionization energies change so little across a row, these elements have important horizontal similarities in chemical properties in addition to the expected vertical similarities.SMgFeNiSeSiTiCrGeBCaCoCuSrMn500ScVAlGaLiNaKRb510152025303540Atomic number
166 B B1+ B B2+ B1+ B3+ B2+ > < > < > < 5 Isoelectronic 10.8115IsoelectronicBoron5+n3e-2e-5+B1+ vs. Be2e-4+5+5+2e-3e-B = 1s22s22p1B1+B><B1+ = Be = 1s22s2n2e-5+1e-5+2e-1e-B2+ vs. Li1e-2e-3+5+B2+B1+>Smaller species (atom or ion) will have the higher ionization energy. The (<) and (>) sign refers to size of atom or ion.<B2+ = Li =1s22s1n1e-2e-5+0e-5+2e-0e-B3+ vs. He0e-2e-2+5+B3+B2+><B3+ = He = 1s2
167 B B1+ B B2+ B1+ B3+ B2+ > < > < > < 5 Isoelectronic 10.8115IsoelectronicBoron5+n3e-2e-5+B1+ vs. Be2e-4+5+B = 1s22s22p1B1+B><B1+ = Be = 1s22s2n2e-5+1e-B2+ vs. Li1e-2e-3+5+B2+B1+><B2+ = Li =1s22s1n1e-2e-5+0e-B3+ vs. He0e-2e-2+5+B3+B2+><B3+ = He = 1s2
168 S S1- S S2- S1- < > < > 16 Sulfur Isoelectronic 32.06616Sulfur16+IsoelectronicS = 1s22s22p63s23p416+2e- 8e- 6e-2e- 8e- 7e-n16+2e- 8e- 7e-17+S1-S<>S vs. ClS1- = Cl1s22s22p63s23p516+2e- 8e- 7e-2e- 8e- 8e-n16+2e- 8e- 8e-18+S2-S1-<S2- = Ar1s22s22p63s23p6>S vs. Ar
170 Ionization Energies (in kilojoules per mole) ElementHHeLiBeBCAl1st1312.12372.5520.3899.5800.71086.5577.62nd5250.77298.51752.22427.22352.81816.73rd3660.04620.72744.84th6223.05th6thIonization energy increases with the removal of each additional electron.Metals have low ionization energy; nonmetals have high ionization energy.This experimental data gives evidence for:1) effect of increasing nuclear charge2) stability of octet3) effect of increased radius4) s & p sublevel in outer levelSUGGESTION: Emphasize that theories came from experimental evidence!Smoot, Price, Smith, Chemistry A Modern Course 1987, page 190
171 Ionization Energies (kJ/mol) ElementHHeLiBeBCAl1st1312.12372.5520.3899.5800.71086.5577.62nd5250.77298.51752.22427.22352.81816.73rd3660.04620.72744.84th6223.05th6thIonization energy increases with the removal of each additional electron.Metals have low ionization energy; nonmetals have high ionization energy.This experimental data gives evidence for:1) effect of increasing nuclear charge2) stability of octet3) effect of increased radius4) s & p sublevel in outer levelSUGGESTION: Emphasize that theories came from experimental evidence!Smoot, Price, Smith, Chemistry A Modern Course 1987, page 190
172 Ionization Energies (kJ/mol) ElementNaMgAlSiPSClAr1st49873657778710631000125515192nd456014451815157518902260229526653rd691077302740322029053375385039454th954010,60011,600435049504565516057705th13,40013,60015,00016,10062706950656073206th16,60018,00018,31019,80021,200849093608780Ionization energy increases with the removal of each additional electron.Metals have low ionization energy; nonmetals have high ionization energy.This experimental data gives evidence for:1) effect of increasing nuclear charge2) stability of octet3) effect of increased radius4) s & p sublevel in outer levelSUGGESTION: Emphasize that theories came from experimental evidence!Herron, Frank, Sarquis, Sarquis, Cchrader, Kulka, Chemistry 1996, Heath, pageShaded area on table denotes core electrons.
173 Ionization Energies (kJ/mol) ElementNaMgAlSiPSClAr1st49873657778710631000125515192nd456014451815157518902260229526653rd691077302740322029053375385039454th954010,60011,600435049504565516057705th13,40013,60015,00016,10062706950656073206th16,60018,00018,31019,80021,200849093608780Ionization energy increases with the removal of each additional electron.Metals have low ionization energy; nonmetals have high ionization energy.This experimental data gives evidence for:1) effect of increasing nuclear charge2) stability of octet3) effect of increased radius4) s & p sublevel in outer levelSUGGESTION: Emphasize that theories came from experimental evidence!Herron, Frank, Sarquis, Sarquis, Cchrader, Kulka, Chemistry 1996, Heath, pageShaded area on table denotes core electrons.
174 ionization energy: the energy required to remove an e– from an atom M + 1st I.E.M e–removes 1st e–M + 2nd I.E.M e–M + 3rd I.E.M e–Each successive ionization requiresmore energy than the previous one.As we go , 1st I.E….decreases.(due to the shielding effect)As we go , 1st I.E….increases.
175 Multiple Ionization Energies 2745 kJ/mole-578 kJ/mole-1817 kJ/mole-AlAl+Al2+Al3+1st Ionizationenergy2nd Ionizationenergy3rd Ionizationenergy• In an atom that possesses more than one electron, the amount of energy needed to remove successive electrons increases steadily.• Define a first ionization energy as (1), a second ionization energy as (2) and in general an nth ionization energy (n) according to the equationE(g) E+(g) + e 1 = 1st ionization energyE+(g) E2+(g) + e 2 = 2nd ionization energyE(n-1)+(g) En+(g) + e n = nth ionization energyThe second, third, and fourth ionization energies of aluminum are higherthan the first because the inner electrons are more tightly held by the nucleus.Smoot, Price, Smith, Chemistry A Modern Course 1987, page 190
177 Factors Affecting Ionization Energy Nuclear ChargeThe larger the nuclear charge, the greater the ionization energy.Shielding effectThe greater the shielding effect, the less the ionization energy.RadiusThe greater the distance between the nucleus and the outerelectrons of an atom, the less the ionization energy.SublevelAn electron from a full or half-full sublevel requires additionalenergy to be removed.Smoot, Price, Smith, Chemistry A Modern Course 1987, page 189
179 Driving Force Full Energy Levels are very low energy. Noble Gases have full orbitals.Atoms behave in ways to achieve noble gas configuration.
180 2nd Ionization EnergyFor elements that reach a filled or half filled orbital by removing 2 electrons 2nd IE is lower than expected.True for s2Alkali earth metals form +2 ions.
181 3rd IE Using the same logic s2p1 atoms have an low 3rd IE. Atoms in the aluminum family form + 3 ions.2nd IE and 3rd IE are always higher than 1st IE!!!
182 Electron AffinityThe energy change associated with adding an electron to a gaseous atom.Easiest to add to group 17.Gets them to full energy level.Increase from left to right atoms become smaller, with greater nuclear charge.Decrease as we go down a group.Electron affinity (EA) of an element E is defined as the energy change that occurs when an electron is added to a gaseous atom:E (g) + e-- E—(g) energy change = EA.• Electron affinities can be negative (in which case energy is released when an electron is added) or positive (in which case energy must be added to the system to produce an anion) or zero (the process is energetically neutral).• Halogens have the most negative electron affinities.• Electron affinities become more negative as we go across a row of the periodic table.Pattern corresponds to the increased effective nuclear charge felt by the valence electrons across a row, which leads to increased electrostatic attractions between the added electron and the nucleus (a more negative EA).The trend is not uniform — some of the alkaline earths (Group 2) and all of the noble gases (Group 18) have effective electron affinities of 0, while the electron affinities for the elements of Group 15 are less negative than those for the Group-14 elements.These exceptions are explained by the groups’ electron configurations.Electron affinities become less negative as we proceed down a column because as n increases, the extra electrons enter orbitals that are increasingly far from the nucleus.Atoms with the largest radii have the lowest ionization energies and have the lowest affinity for an added electron.There are two major exceptions to this trend:1. Electron affinities of elements B through F in the second row of the periodic table are less negative than those of the elements immediately below them in the third row.2. Electron affinities of the alkaline earths become more negative from Be to Ba.Second and higher electron affinities:E(g) + e-- E—(g) energy change = EA1E—(g) + e-- E energy change = EA2• First electron affinity can be 0 or negative, depending on the electron configuration of the atom.• Second electron affinity is always positive because the increased electron-electron repulsions in a dianion are far greater than the attraction of the nucleus for the extra electrons.
183 Ionic Size Cations form by losing electrons. Cations are smaller that the atom they come from.Metals form cations.Cations of representative elements have noble gas configuration.
184 Ionic size Anions form by gaining electrons. Anions are bigger that the atom they come from.Nonmetals form anions.Anions of representative elements have noble gas configuration.
185 Formation of Cation sodium atom Na sodium ion Na+ 11p+ 11p+ e- e- e- loss ofone valenceelectron11p+e-e-e-e-e-e-
186 Formation of Anion chlorine atom chloride ion Cl1- Cl 17p+ 17p+ e- gain ofone valenceelectrone-e-e-e-e-e-e-e-17p+e-e-e-e-e-e-e-e-e-e-
187 Formation of Ionic Bond chloride ionCl1-17p+e-sodium ionNa+11p+
189 Summary of Periodic Trends Objectives:To predict a physical property for an element given the values of other elements in the same group.To predict a chemical formula for a compound given the formulas of other compounds containing an element in the same group.
190 Metallic Characteristics metallic character increasesnonmetallic character increasesmetallic character increases• Elements with the highest ionization energies are those with the most negative electron affinities, which are located in the upper-right corner of the periodic table.• Elements with the lowest ionization energies are those with the least negative electron affinities and are located in the lower-left corner of the periodic table.• The tendency of an element to gain or lose electrons is important in determining its chemistry.• Various methods have been developed to describe this tendency quantitatively.• The most important method is called electronegativity (), defined as the relative ability of an atom to attract electrons to itself in a chemical compound.nonmetallic character increases
191 Metallic Characteristic metallic character increasesnonmetallic character increasesmetallic character increasesnonmetallic character increases
192 Summary of Periodic Trends Shielding is constantAtomic radius decreasesIonization energy increasesElectronegativity increasesNuclear charge increases1AIonization energy decreasesElectronegativity decreasesNuclear charge increasesAtomic radius increasesShielding increasesIonic size increases2A3A4A5A6A7A• Elements with the highest ionization energies are those with the most negative electron affinities, which are located in the upper-right corner of the periodic table.• Elements with the lowest ionization energies are those with the least negative electron affinities and are located in the lower-left corner of the periodic table.• The tendency of an element to gain or lose electrons is important in determining its chemistry.• Various methods have been developed to describe this tendency quantitatively.• The most important method is called electronegativity (), defined as the relative ability of an atom to attract electrons to itself in a chemical compound.Rules for assigning oxidation states are based on the relative electronegativities of the elements — the more-electronegative element in a binary compound is assigned a negative oxidation stateElectronegativity values used to predict bond energies, bond polarities, and the kinds of reactions that compounds undergoTrends in periodic properties:1. Atomic radii decrease from lower left to upper right in the periodic table.2. Ionization energies become more positive, electron affinities become more negative, and electronegativities increase from the lower left to the upper right.Ionic size (cations) Ionic size (anions)decreases decreases
195 Essential Elements Elements in organic matter H He Major minerals Li 1He2Major mineralsLi3Be4B5C6N7O8F9Ne10Trace elementsNa11Mg12Al13Si14P15S16Cl17Ar18K19Ca20Sc21Ti22V23Cr24Mn25Fe26Co27Ni28Cu29Zn30Ga31Ge32As33Se34Br35Kr36Rb37Sr38Y39Zr40Nb41Mo42Tc43Ru44Rh45Pd46Ag47Cd48In49Sn50Sb51Te52I53Xe54Minerals are considered the inorganic elements of the body. Minerals fall into two categories – the major minerals and the trace minerals, or trace elements, as they are sometimes called.Trace elements are minerals with dietary daily requirements of 100 mg or less. They are found in foods derived from both plants and animals. Though these elements are present in very small quantities, they perform a variety of essential functions in the body.Elements that are absolutely required in the diets of humans are called essential elements (highlighted in purple).Essential elements are restricted to the first four rows of the periodic table with only two exceptions (Mo and ).An essential element is one that is required for life and whose absence results in death.An element is considered to be essential if a deficiency consistently causes abnormal development or functioning and if dietary supplementation of that element and only that element prevents this adverse effect.Cs55Ba56La57Hf72Ta72W74Re75Os76Ir77Pt78Au79Hg80Tl81Pb82Bi83Po84At85Rn86Davis, Metcalfe, Williams, Castka, Modern Chemistry, 1999, page 748
196 Trace Elements in Biological Systems Of the 100 known elements, 28 are known to be essential for the growth of at least one biological species, and only 19 are essential to humans.The following makes some elements essential:1. The element must have some unique chemical property that an organism can use to its advantage and without which it cannot survive.2. Adequate amounts of the element must be available in the environment in an easily accessible form.• Many of the elements essential to life are necessary in only small amounts (trace elements).Elements that are present in trace amounts can exert large effects on the health of an organism.Elements function as part of an amplification mechanism, in which a molecule containing a trace element is an essential part of a larger molecule that acts in turn to regulate the concentrations of other molecules.Essential trace elements in mammals have four general roles:1. They can behave as macrominerals.2. They can participate in the catalysis of group transfer reactions.3. They can participate in oxidation-reduction reactions.4. They can serve as structural components.The macrominerals (sodium, magnesium, potassium, calcium, chlorine, and phosphorus) are found in large amounts in biological tissues.• Macrominerals are present as inorganic compounds, either dissolved or precipitated.• All form monatomic ions except phosphorus.• Body fluids of all multicellular organisms contain high concentrations of these ions.• Substantial energy is required for transport of these ions across cell membranes — selection of ion pumps based on differences in ionic radius.• It is important to maintain optimum levels of macrominerals because temporary changes in their concentrations within a cell affect biological functions.Trace metal ions play crucial roles in many biological group transfer reactions.In these reactions, a recognizable functional group is transferred from one molecule to another.To neutralize the negative charge on the molecule that is undergoing the reaction, many biological reactions of this type require the presence of metal ions.Effectiveness of a metal ion depends on its charge and radius.The third important role of trace elements is to transfer electrons in biological oxidation-reduction reactions.Because most transition metals have multiple oxidation states separated by only one electron, they are uniquely suited to transfer multiple electrons one at a time.Many of the p-block elements are suited for transferring two electrons at once.Trace elements act as essential structural components of biological tissues or molecules.The trace element stabilizes a particular three-dimensional structure of the biomolecule in which it is found.Copyright 2007 Pearson Benjamin Cummings. All rights reserved.
197 Classification of the Essential Elements Most living matter consists primarily of bulk elements—oxygen, carbon, hydrogen, nitrogen, and sulfur. They are the building blocks of the compounds that make up our organs and muscles; they also constitute the bulk of our diet.Six elements—sodium, magnesium, potassium, calcium, chlorine, and phosphorus—are called macrominerals and provide essential ions in body fluids and form the major structural components of the body.Remaining essential elements called trace elements and are present in small amounts.Copyright 2007 Pearson Benjamin Cummings. All rights reserved.
200 Oxidation State of Elements The most stable atom will be one that has a completely filled outer valence region (complete octet with the exception of HydrogenGroup 1=lose 1 electron = +1 ionGroup 2 = lose 2 electrons = +2 ionGroup 13 = lose 3 electrons = +3 ionGroup 14 = lose 4 electrons = +4 ionGroup 15= gain 3 electrons = -3 ionGroup 16 = gain 2 electrons = -2 ionGroup 17 = gain 1 electron = -1 ionGroup 18 = gain 0 electrons = no charge
201 Various Ions Group 16 = gain 2 electrons = -2 ion The most stable atom will be one that has a completely filled outer valence region (complete octet with the exception of HydrogenGroup 1=lose 1 electron = +1 ionGroup 2 = lose 2 electrons = +2 ionGroup 13 = lose 3 electrons = +3 ionGroup 14 = lose 4 electrons = +4 ionGroup 15= gain 3 electrons = -3 ionGroup 16 = gain 2 electrons = -2 ionGroup 17 = gain 1 electron = -1 ionGroup 18 = gain 0 electrons = no charge
202 Oxidation States of Elements 18Groups2Li1+Be2+F1-O2-Cl1-Na1+Te2-Al3+S2-Br1-K1+Te2-Zn2+Ga3+Se2-I1-Rb1+Te2-Ag1+In3+Te2-Many elements have a tendency to gain or lose enough electrons to attain the same number of electrons as the noble gas closest to them in the periodic table.Monatomic ions contain only a single atom.Charges of most monatomic ions derived from the main group elements are predicted by simply looking at the periodic table and counting how many columns an element lies from the extreme left or right.Transition metals form cationswith various charges.Cs1+Te2-
203 Chemical Bonding Ionic Covalent Metal (cation) with non-metal (anion)Transfer of electron(s)Strong bond…high melting pointCovalentNon-metal with non-metalSharing of electron(s)Non-polar (equal distribution of electrons)Polar (uneven electron distribution)Weak bonds…low melting pointsSingle, double and triple bondsMetallic (nuclei in a “sea” of shared electrons)
204 First Four Energy Levels Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 334
205 Modern Atomic Structure 2p3p4p3d4d4fSublevel designationn = 1n = 2n = 3n = 4An orbital for a hydrogenatom. The intensity of thedots shows that the electronspends more time closer tothe nucleus.The first four principal energylevels in the hydrogen atom.Each level is assigned aprincipal quantum number n.The types of orbitals on eachof the first four principalenergy levels.Hein, Arena, Foundations of College Chemistry, 2000, page 202
206 SublevelsZumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 334
207 Principal Level 2 Divided Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 334
211 Element BrochureResearch any element you choose and make an informational brochureto tell about your element. Creativity may be needed.Technology assignment (Publisher brochure)Minimum of three references (one textbook and one internet site)Title, author, year published and URLNot ALL writing or not ALL bullets in brochureUse graphics and pictures to add visual appealcaptions with picturesFront: Name of element, picture/graphic, your name, class hourBack: References, graphicInside flap: facts – melting point, atomic number, Bohr model, etc…Opened brochure (three sections…interesting facts, history, uses)Brochure should look neat. Writing should be 12 point font.Use only 1 or 2 fonts in entire brochure.Element Project Example Brochure (Publisher)
212 Autobiography of an Element I am Promethium, Pm for short. I was named after Prometheus, whoaccording to Greek mythology, brought fire to man. I'm a member of theLanthanide (rare earth) elements. My family name is derived from the Greeklanthum, meaning “to escape notice”.You may not have noticed me around before, as I have no naturallyoccurring isotopes. True to family tradition, I managed to avoid positiveidentification until O. Ermetsa first isolated 350 mg 147Pm from 6000tons apatite. Once discovered, I was immediately put to work. Large quantitiesof 147Pm salts (luminesce pale blue or green) are used in luminescent paintfor watch dials. Another job I've held is as a part in a beta-voltaic battery.You may think there is not enough of me to go around. However, everyday,my cousin 147Sm transforms into Promethium by radioactive decay (at a rate of0.07%/day). Also, I'm a rare earth fission product of uranium. Please get toknow me. I'll be around for awhile with 147Pm half-life of 2.5 years and 145Pmhalf-life of 30 years.
214 O F Cl Ar H He Xe Kr Neon Advertisement Oxygen Fluorine Chlorine 15.99918.99835.453HydrogenNeonArgonArH1.0079$10,89539.948HeliumXenonKryptonHeXeKr4.0026131.3083.800*Neon Highline Sedan, shown: $13,770 nicely equipped. MSRPs include destination, exclude tax. *Achieved with premium unleaded fuel.When utilizing the Ideal Gas Equation, PV = nRT, remember that temperature is measured in Kelvins.
215 Molar Masses of the Elements Periodic Table trends plotMolar Masses of the Elements
216 Attraction and Repulsion of Electrical Charges +---++Particles with unlike chargesattract one another.Particles with like chargesrepel one another.Ralph A. Burns, Fundamentals of Chemistry 1999, page 96
217 Exception!Two exceptions to the simple –ide ending are the diatomic oxide ions,O22- and O21-.O22- is called peroxideO21- is called superoxide.Note the differences.barium oxide __________barium peroxide __________BaOBaO2Ba2+sodium oxide __________sodium peroxide __________Na2ONa2O2Na1+Do Not Reduce to lowest terms!potassium oxide __________potassium superoxide __________K2OKO2K1+
219 Resources - Periodic Table ObjectivesEpisode 7 – The Periodic TableWorksheet - vocabularyGeneral Chemistry PPActivity - aliens cards: A B keyActivity - coloring periodic tableWorksheet - periodic table paragraphWorksheet - ionization energiesVideo 07: Periodic Table The development and arrangement of the periodic table of elements is examined. (added 2006/10/08) World of Chemistry > 08: Chemical BondsLab - periodic trends databaseProject - element brochure example timelineWorksheet - periodic table textbook questionsWorksheet - textbook questions (general)Outline (general)