The most fundamental concept in The Periodic Table The most fundamental concept in CHEMISTRY!

Dmitri Mendeleev Russian Invented periodic table Organized elements by properties Arranged elements by atomic mass Predicted existence of several unknown elements Element 101 named for him Dmitri 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 table Dmitri 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

FYI Mendeleev’s Early Periodic Table The ? Indicate undiscovered elements TABELLE II GRUPPE I GRUPPE II GRUPPE III GRUPPE IV GRUPPE V GRUPPE VI GRUPPE VII GRUPPE VIII ___ ___ ___ ___ RH4 RH3 RH2 RH R2O RO R2O3 RO2 R2O5 RO3 R2O7 RO4 REIHEN 1 2 3 4 5 6 7 8 9 10 11 12 H = 1 Li = 7 Be = 9.4 B = 11 C = 12 N = 14 O = 16 F = 19 Na = 23 Mg = 24 Al = 27.3 Si = 28 P = 31 S = 32 Cl = 35.5 ? K = 39 Ca = 40 __ = 44 Ti = 48 V = 51 Cr = 52 Mn = 55 Fe = 56, Co = 59, Ni = 59, Cu = 63 (Cu = 63) Zn = 65 __ = 68 __ = 72 As = 75 Se = 78 Br = 80 Rb = 85 Sr = 87 ? Yt = 88 Zr = 90 Nb = 94 Mo = 96 __ = 100 Ru = 104, Rh = 104, Pd = 106, Ag = 108 In 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 = 112 In = 113 Sn = 118 Sb = 122 Te = 125 J = 127 Cs = 133 Ba = 137 ? Di = 138 ? Ce = 140 __ __ __ __ __ __ __ ( __ ) __ __ __ __ __ __ __ __ ? Er = 178 ? La = 180 Ta = 182 W = 184 __ Os = 195, Ir = 197, Pt = 198, Au = 199 (Au = 199) Hg = 200 Tl= 204 Pb = 207 Bi = 208 __ __ __ __ __ Th = 231 __ U = 240 __ __ __ __ __ From Annalen der Chemie und Pharmacie, VIII, Supplementary Volume for 1872, p. 151.

The ? Elements’ Properties are Predicted Property Mendeleev’s Predictions in 1871 Observed Properties Molar Mass Oxide formula Density of oxide Solubility of oxide ? 44 g M2O3 3.5 g / ml Dissolves in acids Scandium (Discovered in 1877) 43.7 g Sc2O3 3.86 g / ml Molar mass Density of metal Melting temperature 68 g 6.0 g / ml Low Dissolves in ammonia solution Gallium (Discovered in 1875) 69.4 g 5.96 g / ml 30 0C Ga2O3 Dissolves in ammonia Color of metal Chloride formula Density of chloride Boiling temperature of chloride 72 g 5.5 g / ml Dark gray High MO2 4.7 g / ml MCl4 1.9 g / ml Below 100 oC Germanium (Discovered in 1886) 71.9 g 5.47 g / ml Grayish, white 900 0C GeO2 4.70 g / ml GeCl4 1.89 g / ml 86 0C Fitting 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 23 In 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,

Modern Periodic Table Henry G.J. Moseley Determined the atomic numbers of elements from their X-ray spectra (1914) Arranged elements by increasing atomic number Look at your periodic table. Notice how atomic mass does NOT go up between elements 27 and 28. H.G.J. Moseley (1887- 1915) 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) 1887 - 1915

Metals, Nonmetals, & Metalloids 1 2 Nonmetals 3 4 5 Metals 6 7 Metalloids Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 349

Review of Properties of Metals, Nonmetals, and Metalloids malleable, lustrous, ductile, conductors of heat and electricity, react with acid and CuCl2 Brittle, dull, poor conductors of heat and electricity, do not react with acids or CuCl2 METALLOIDS (Semi-metals) Can have properties of both metals and non-metals. (used in computer chips)

Diagram of an Atom

Vertical Columns are called Groups or Families. Elements of the same group have similar properties and behave alike chemically. Why is this??

Valence Electrons Electrons on the outermost shell of an atom Participate in bonding and determine how an element will bond when making compounds Electrons on outside shell are valence electron; oxygen has 6 Oxygen Atom

Pattern for Counting Valence Electrons Ignore the ‘1’ Only 2

The Families of The Periodic Table Noble gases Alkaline earth metals Halogens 1 18 H 1 He 2 2 13 14 15 16 17 Li 3 Be 4 B 5 C 6 N 7 O 8 F 9 Ne 10 Na 11 Mg 12 3 4 5 6 7 8 9 10 11 12 Al 13 Si 14 P 15 S 16 Cl 17 Ar 18 Click on this to see Alkali metals In action!! Transition metals K 19 Ca 20 Sc 21 Ti 22 V 23 Cr 24 Mn 25 Fe 26 Co 27 Ni 28 Cu 29 Zn 30 Ga 31 Ge 32 As 33 Se 34 Br 35 Kr 36 Alkali metals Rb 37 Sr 38 Y 39 Zr 40 Nb 41 Mo 42 Tc 43 Ru 44 Rh 45 Pd 46 Ag 47 Cd 48 In 49 Sn 50 Sb 51 Te 52 I 53 Xe 54 Cs 55 Ba 56 * Hf 72 Ta 73 W 74 Re 75 Os 76 Ir 77 Pt 78 Au 79 Hg 80 Tl 81 Pb 82 Bi 83 Po 84 At 85 Rn 86 Fr 87 Ra 88 Y Rf 104 Db 105 Sg 106 Bh 107 Hs 108 Mt 109 Uun 110 Uuu 111 Uub 112 Uuq 113 Uuh 116 Uuo 118 * Lanthanides La 57 Ce 58 Pr 59 Nd 60 Pm 61 Sm 62 Eu 63 Gd 64 Tb 65 Dy 66 Ho 67 Er 68 Tm 69 Yb 70 Lu 71 Y Actinides Ac 89 Th 90 Pa 91 U 92 Np 93 Pu 94 Am 95 Cm 96 Bk 97 Cf 98 Es 99 Fm 100 Md 101 No 102 Lr 103

Practice the information just learned by completing the Homework on packet page 31

Horizontal Rows are called Periods. The Period number tells how many energy levels, or shells, an element has. LABEL the periods 1-7 on your periodic table.

Hide and Seek! Find the element that has 3 energy levels and is a member of the Halogen family. Chlorine Find the element that has 2 valence electrons and 3 energy levels. Magnesium

Let’s blow up Carbon to have a better look at what information is there Atomic number (tells # of protons and electrons in a Neutral atom) Element name Element symbol Atomic mass “Atomic mass” is the average mass number of all the Carbon atoms on Earth.

Isotope Atoms of the same element with different number of neutrons. Isotopes of an element will have different masses. Ex: two isotopes of carbon Carbon-12 has a mass of 12 Carbon-14 has a mass of 14

Protons have a mass = 1 amu Neutrons have a mass = 1 amu Electrons have a negligible mass How do you calculate the mass of an atom? Mass number = protons + neutrons

Try These An atom of nitrogen has 8 neutrons. What is its mass number? 15 A uranium atom has a mass number of 235. How many neutrons does it have? 143 An element has a mass number of 56 and 30 neutrons. What element is it? iron

There isn’t a “regular” carbon here; there are two isotopes There isn’t a “regular” carbon here; there are two isotopes. The two symbols shown below & right are called “isotopic symbols”.

Isotopic Symbol Represents mass number 12 C 6 Represents Atomic Number

Your Turn Write the isotopic symbol for an isotope of Calcium that has 21 neutrons. 41 Ca 20 How many protons does this isotope have? How many electrons does this isotope have? How many neutrons does this isotope have? 20 20 21

Isotopes of Boron Boron-10 and Boron-11 Which is more abundant (meaning more of it naturally exists)? There must be more Boron-11 if the average mass is 10.811.

Practice the information just learned by completing the Homework on packet page 35 and 37. Note! On p 37, do not do #4,6 and 9 until later!!!

So, Atoms Can Change! Changing different parts of the atom may or may not change it’s behavior What happens if we change the number of protons in an atom? You change the element An atom with 12 protons is… Magnesium Add a proton, atom is now… Aluminum (changing number of protons is not common)

What happens if you change the number of neutrons in an atom? You change the isotope (or form of the atom)

What happens if you change the number of electrons in an atom? You create an ion!.... Wait what is that? When an atom gains or loses electrons and therefore is no longer neutral.

Atoms vs. Ions Atoms can gain or lose valence electrons. Once they do, they are called IONS. Why become an ion? in order to achieve a full outer energy level (or full octet) like the noble gases A full energy level has less energy, and therefore is more stable. Ions can ‘bond’ to form compounds- Ionic bonds

A Negatively Charged Ion is called Anion (pronounced: ‘an-eye-on”) Example: Cl-

Example of an anion Cl (atom) has 17 positive protons and 17 negative electrons + ++++++++++++++++ (17 protons) - - - - - - - - - - - - - - - - - (17 electrons) Atom is neutral because it has equal numbers of protons and electrons. What if a chlorine atom gained an electron? There is now one more electron! This makes for a total -1 charge. We now have a chloride ion 17 protons 18 electrons

A Positively Charged Ion is called Cation (pronounced: ‘cat-eye-on’) Example: Na+

Example of a cation Na (atom) has 11 positive protons and 11 negative electrons +++++++++++ (11 protons) - - - - - - - - - - - (11 electrons) Atom is neutral because it has equal numbers of protons and electrons. What if a sodium atom lost an electron? There is now one more proton! This makes for a total +1 charge. We now have a sodium ion 11 protons 10 electrons

Ions Remember, atoms try to achieve a full outer energy level by gaining or losing valence electrons. This is known as the octet rule…most atoms try to get 8 electrons in their outer level. EXCEPTION! If there is only one energy level, a full energy level is only two electrons. Atoms always do what is easier to get to the full octet!

Formation of an ion. Sodium is not happy having just one valence electron. It wants to have a full outer shell It could either gain 7 more electrons to have a full third level Or it could lose 1 electron and have a full second level Which do you think it will do? sodium atom Na e- e- e- e- e- e- 11p+ e- e- e- e- e- e-

It is easier to lose one electron It will NEVER gain 7! sodium atom Na sodium ion 11p+ e- e- e- e- e- e- e- loss of one valence electron to attain a full outer energy level 11p+ e- e- e- e- e- e- Because Na lost one electron, it has a +1 charge. It has become the Na+ ion.

Formation of an ion Chlorine is not happy having only 7 valence electrons. It wants to have a full outer shell It could either gain 1 more electron to have a full third level Or it could lose 7 electrons and have a full second level Which do you think it will do? chlorine atom Cl e- e- e- e- e- e- e- 17p+ e- e- e- e- e- e- e- e- e- e-

It is easier to gain 1 electron It will NEVER lose 7! chlorine atom Cl chloride ion 17p+ e- e- e- e- e- e- e- e- gain of one valence electron to attain a full outer energy level e- 17p+ e- e- e- e- e- e- e- e- e- e- Because Cl gained one electron, it has a -1 charge. It has become the Cl- ion.

First 18 elements: Energy levels drawn, showing valence electrons Number of valence electrons written above familes Notice the exception for Helium

+1 -3 +2 -2 -1 Number of valence electrons Lose 1 xx xx Gain3 FULL Lose 2 Gain 2 +1 Gain 1 -3 +2 How many electrons will each family gain or lose to get a full outer energy level? What charge will each family’s ions be? -2 -1

Determine Charge of the Following Ions Sodium Ion +1 Fluoride Ion -1 Bromide Ion Calcium Ion +2 Copper Ion Depends on what it is bonded with

Exceptions to Ion Charge Pattern Ag is always +1 Zinc is always +2 Aluminum is always +3

Now write an isotopic symbol for a chlorine ion with a mass number of 37. Cl- 17 17 How many protons does this isotope have? How many electrons does this isotope have? How many neutrons does this isotope have? 18 20

Begin Homework! Finish Isotope worksheet, pkt p 37 #4,6 and 9 Complete Ions worksheet, pkt p 41 Read and take notes on Book section B.10 found on p. 65-67. Put notes on pkt p 40.