2. Big Idea #2: CHEMISTRY’S PERIODIC LAW: Sorting the Elements Brett Myers, Maureen McEnery, Cari Murray

3. Periodic Table 1869/1871

4. Where do we start? With matter!
Atoms
Orbitals
hierarchy
Nucleus
Neutrons
Uncharged
Protons
Positively charged
Electrons
Negatively charged
Progression of scientific thought 1

5. Emperically Probing the Element
Chemistry and Physics attempt to analyze atoms.
Chemistry deals with both the structure and the properties of atoms: i.e. whether or how they interact with other atoms.
Chemists deal with groups of atoms they can sense (touch, small,
probe, manipulate).
Groups of the same kind
of atoms are called elements.

6. The BIG QUESTION: How do elements behave under various conditions?
Effect of temperature?
Effect of pressure?
Effect of combining them?
All of these observations lead to formulating hypotheses about the nature of elements.
To understand the nature of an element is similar to the way you come to understand a new acquaintance.

7. Universal Elements: The Greeks
Thales BC Water
Anaximenes BC Air
Heraclitus BC Fire
Empedocles BC Earth, water, air,
fire could produce any
substance
Aristole BC Aether
everything beyond
earth
Progression of scientific thought 2

8. Universal Elements: The Egyptians
Bolos of Mendes 200 BC Alloys
come from mixtures
of substances
(brass = copper and zinc)
Experimentation that helped provide insight into the nature of matter.
They heated rocks with charcoal to produce
metals, made glass from sand, and made
bricks from clay.
Progression of scientific thought 3

9. Alchemy: Big Failure/Bigger Success
Alchemists were the early forerunners to chemists.
Alchemy is derived from the Greek words meaning to separate
and to join together in the 16th century
Formulated recipes for gold and conducted the
corresponding experiments.
Transmutation is the conversion of one element
to another, was never achieved by mixing
substances with each other.
Efforts contributed to the advance of new
materials and techniques and their observations
led to more valid hypotheses.
"Renel the Alchemist",
by Sir William Douglas
1853
Progression of scientific thought 4

10. Physical and Chemical Properties of the Elements
Chemists in the
19th century
Cataloging the
behavior of elements
60 elements
were known
Physical properties:
Melting point
Density
Chemical properties
Reactivity with
other elements
Observation similar
chemical behavior
Boiling Point
Atomic Mass
Is there a relationship between
Physical & Chemical Properties
of the Elements ?
Progression of scientific thought 5

11. In 1860, the atomic mass (ma) of 60 elements were known
Atomic mass is a physical property that is the measure of the mass of an atom of one element compared to the mass of another.
H has lowest atomic mass = 1
Li = 7
Be = Ca = 40
B = Al = 27
C = Si = 28
N = P = 31
O = S = 32
F = Cl = 35
Na = K = 39
Mg = Ti = 48

12. Repeat Performance (Triads)
1817 and Johann Dobereiner Germany
Published articles in which he examined the properties
of sets of elements that he called triads (e.g. Li, Na, K)
Elements in each triad have similar
chemical properties
The atomic mass of the second
element in the triad is approximately
equal to the average of the atomic
mass of the other two
( Li = 7, Na = 23, K = 39).
Progression of scientific thought 6

13. Repeat Performance (Octaves)
1863 – John Newland England
Composed a Law of Octaves
When elements are listed in increasing
atomic mass, the eighth is similar in
chemically properties to the first
His work was not taken seriously
Progression of scientific thought 7

14. A Periodic Table (for One?)
Historic rivals in publishing their own version
of the Periodic Table
Julius Lothar Meyer Dmitri Ivanovich Mendeleev
(1834–1907) (1830–1895)
MEYER
MENDELEEV
Progression of scientific thought 8

15. The Year
In 1859, Darwin in On the Origin of Species by Means of Natural Selection or the Preservation of Favored Races in the Struggle for Life,
In 1859, cocaine was isolated and patented by Merck three years later.
In 1859, Kolbe synthesized salicylic acid.
In 1859, Robert Wilhelm Bunsen discovered that each element produces its own characteristic set of lines in the spectrum.  Thus was 'spectography' invented, which, with photography, enabled the subsequent advances in astronomy. 
Gustav Robert Kirchhoff followed up Bunsen's discovery and "made the first identification of the presence of any element outside the Earth when he found the characteristic sodium lines in the spectrum of light from the Sun".    
In 1860, Pierre Eugöne Marcelin Berthelot, in Chimie organique fondeé sur la synthöse, described the synthesis of several carbon compounds.
In 1860, Bunsen and Kirchhoff, in Chemische Analyse durch Spektralbeobachtungen, recounted their discovery of cesium and rubium. 
In 1860, Maxwell, in "Illustrations of the dynamical theory of gases," showed that viscosity is independent of density, or pressure.
In 1861, William Crookes, using a spectroscope, announced a new element, 'thallium.'
In 1861, Maxwell, in "On Physical Lines of Force," announced his discovery that some of the properties of the vibrations in the magnetic medium are identical with those of light.
In 1861, Anders Jonas Ångström, using a spectroscope, confirmed the presence of hydrogen in the Sun.
     

16. The Karlsruhe Congress was an international meeting of chemists held
in Karlsruhe, Germany from September 3, 1860 to September 5, 1860.
The Karlsruhe Congress was called so that European chemists could discuss
matters of chemical nomenclature, notation, and atomic weights.
Attendance
According to Wurtz's list,[5] the congress was attended by the scientists listed below.
Belgium. Brussels: Stas; Ghent: Donny, A. Kekulé
Germany. Berlin: Ad. Baeyer, G. Quinke; Bonn: H. Landolt; Breslau: Lothar Meyer;
Kassel: Guckelberger,; Klausthal: ; Darmstadt: E. Winkler; Erlangen: v. Gorup-Besanez; Freiburg i. B.: v. Babo, Schneyder;
Giessen: , H. Kopp, ; Göttingen: F. Beilstein; Halle a. S.: W. Heintz; Hanover: Heeren;
Heidelberg: Becker, O. Braun, R. Bunsen, L. Carius, E. Erlenmeyer, , Schiel; Jena: Lehmann, H. Ludwig;
Karlsruhe: A. Klemm, R. Muller, J. Nessler, Petersen, K. Seubert, Weltzien; Leipzig: O. L. Erdmann, Hirzel, Knop,
Kuhn; Mannheim: Gundelach, Schroeder; Marburg a. L.: R. Schmidt, ; Munich: Geiger; Nuremberg: v. Bibra;
Offenbach: Grimm; Rappenau: Finck; Schönberg: R. Hoffmann; Speyer: Keller, Mühlhaüser; Stuttgart: v. Fehling, W. Hallwachs;
Tübingen: Finckh, A. Naumann, A. Strecker; Wiesbaden: Kasselmann, R. Fresenius, C. Neubauer;
Würzburg: Scherer, v. Schwarzenbach
United Kingdom. Dublin: Apjohn A.; Edinburgh: Al. Crum Brown, Wanklyn, F. Guthrie; Glasgow: Anderson;
London: , G. C. Foster, Gladstone, Müller, Noad, A. Normandy, Odling; Manchester: Roscoe;
Oxford: Daubeny, G. Griffeth, F. Schickendantz; Woolwich: Abel
France. Montpellier: A. Béchamp, A. Gautier, C. G. Reichauer; Mülhousen i. E.: Th. Schneider; Nancy: J. Nicklès;
Paris: Boussingault, Dumas, C. Friedel, , Le Canu, , Alf. Riche, P. Thénard, Verdét, C.-A. Wurtz;
Strasbourg i. E.: Jacquemin, Oppermann, F. Schlagdenhaussen, P. Schützenberger; Tann: Ch. Kestner, Scheurer-Kestner
Italy. Genoa: Cannizzaro; Pavia: Pavesi.
Mexico. Posselt
Austria. Innsbruck: Hlasiwetz; Lemberg: Pebal; Pesth: Th. Wertheim; Vienna: V. v. Lang , A. Lieben, Folwarezny, F. Schneider
Portugal. Coïmbra: Mide Carvalho
Russia. Kharkov: Sawitsch; St. Petersburg: Borodin, Mendeleev, , Zinin N.;
Poland. Warsaw: T. Lesinski,
Sweden. Harpenden: J. H. Gilbert; Lund: Berlin, C. W. Blomstrand; Stockholm: Bahr
Switzerland. Bern: C. Brunner, H. Schiff; Geneva: C. Marignac; Lausanne: Bischoff; Reichenau bei Chur: ; Zurich: J. Wislicenus
Spain. Madrid: R. de Suna

17. Impact of Karlsruhe Congress of 1860
On the meeting's last day reprints of Cannizzaro's 1858 paper on atomic weights, in which he utilized earlier work by Avogadro, were distributed. Cannizzaro's efforts exerted a heavy and, in some cases, an almost immediate influence on the delegates. Lothar Meyer later wrote that on reading Cannizzaro's paper, "The scales seemed to fall from my eyes."[3]
As long as there were uncertainties over atomic weights then the compositions of many compounds remained in doubt. An important long-term result of the Karlsruhe Congress was the adoption of the now-familiar atomic weights (actually, atomic masses). Following the Karlsruhe meeting, values of about 1 for hydrogen, 12 for carbon, 16 for oxygen, and so forth were adopted. This was based on a recognition that certain elements, such as hydrogen, nitrogen, and oxygen, were composed of diatomic molecules and not individual atoms.

18. Julius Lothar Meyer
In 1864, five years before the first announcement of a Periodic System by Mendeleev, Meyer produced a table of just 28 elements listed by their valence.
The 28 elements were almost entirely main group elements. He incorporated transition metals in another table in 1868 which listed the elements in increasing weight order with elements with the same valence in a given column.
Annalen der Chemie, Supplementband 7, 354 (1870).
Progression of scientific thought 9

19. Dimitri Mendeleev
Progression of scientific thought 11

20. Repeat Performance (Periods)
1869 Dimitri Mendeleev Russian
Decision to arrange elements in horizontal rows of increasing atomic mass
The lightest element, H, was the sole member of the first row
Second row began with Li and continued to F
When he reached the next element, Na, whose chemical properties were quite similar to those of Li*, he started a new row, placing Na below Li.
Continued until he got to K*, which he placed below Na.
* Li, Na, and K react violently with water
Progression of scientific thought 10

23. A pattern emerges!
The table that was produced show elements in horizontal rows or periods of increasing atomic mass.
Vertical columns were members of groups with similar chemical properties
Chemical properties were occurring in periodic fashion
For example: Be, Mg, and Ca all react with O to produce a white solid compound that reacts slowly with water.
Progression of scientific thought 12

24. Empirical testing, classification,
Periodic Table 1869/1871
Empirical testing, classification,
and prediction

25. The Boldness of the Gap The next known element after Ca (M = 40)
was Ti (M = 48)
Comparing chemical properties of Ti to Al and B
suggested that Ti was NOT similar to Al or B.
Similarity in the way that Si formed oxides,
compared to how Ti formed oxides suggested
Ti and Si should be arranged in the same vertical
column.
Mendeleev created a gap in the table.

26. Filling in the Gap The gap is a prediction
Mendeleev’s hypothesis was that the chemical properties of the elements recur in a periodic fashion or more specifically,
That their chemical properties were a function of their atomic mass
The missing element should have the following properties:
Chemically similar to B and Al
Atomic mass between Ca (45) and Ti (48)
Scandium (Sc) discovered in 1879
Sc atomic mass of 45
Progression of scientific thought 13

27. Make the rules and break the rules
Mendeleev’s predictions, when met, provided further credibility for his hypothesis
Moreover, he was the first to break from rigid adherence to the hypothesis that chemical properties of the elements are periodic functions of their atomic masses
I as a case-in point. I has atomic mass of 127, which Te has atomic mass of 128.
I is more chemically similar to F, Cl, and Br; while Te is more chemically similar to O, S and Se.
I was placed in the F, Cl, and Br vertical row.
Mendeleev on Russian TV
Progression of scientific thought 14

28. Elements are grouped by chemical similarity: the classification of groups

29. Alkali metals: Alkali metals are very reactive chemical species which readily lose their one valence electron to form ionic compounds with nonmetals.
Alkaline earth metals: The alkaline earth metals, as a group, share charactertic properties.
Lanthanoids:The lanthanide series is the group of elements in which the 4f sublevel is being filled.
Actinoids: Usually, the actinides are considered to be elements 90 (thorium) through 103 (lawrencium). Otherwise, the actinides are defined according to their common properties.
Transition Metals: A Transition Metal is an element from the B group of the periodic table. Transition metals have partially filled d sublevel orbitals.
Poor Metals: In chemistry, the term post-transition metal is used to describe the category of metallic elements to the right of the transition elements on the periodic table.
Other non-metals: One of the elements which do not exhibit metallic properties, generally located in the upper righthand corner of the Periodic Table.
Noble gases: Any of the elements found in Group 8 at the far right of the Periodic Table

30. Dmitrii Mendeleev (1834-1907) FARADAY LECTURE:
The Periodic Law of the Chemical Elements.
Journal of the Chemical Society, 55, (1889)
By Professor MENDELÉEFF
(Delivered before the Fellows of the Chemical Society on Tuesday, June 4th, 1889)

31. Atomic Numbers to the Rescue
Unknown in Mendeleev’s time was the concept
of atomic number.
Atomic number refers to the number of protons
in the nucleus of the atom.
It is a more fundamental guide to correlating
chemical properties than
atomic mass
Atomic number of He is 2,
while atomic mass
of He is 4.
Progression of scientific thought 15

32. Room to Grow The number of known elements is about 112.
To accommodate all of these elements, the
periodic Table had to be modified and expanded.
As a result, Sc is no longer placed under
B and Al, and Ti is no longer placed under
Ca and Si.
Progression of scientific thought 16

33. A REALLY BIG IDEA
The Periodic Table is a really big idea because of its explanatory and predictive power.
It makes predictions about the existence of elements to fill the gaps within the periodic table.
It makes predictions about the existence of elements whose atomic numbers are beyond those that are presently known.

34. Interactive Periodic Tables
Periodic Table 3 (with video)

36. The tail end of the table
The huge gap at the tail of the Periodic table demands to be filled.
Scientists all competing with each other for the distinction of filling in these gaps.
To test the periodic law, upon synthesizing a new element, they study the element’s properties relative to its position in the table.
Progression of scientific thought 17

37. Element Recycling To create new elements, new nuclei must be made.
Altering the number of protons
in the nucleus of an atom
converts that atom into an
atom of another element.
Isotopes
Atomic reactivity
Progression of scientific thought 18

38. The Name Game Until recently, the group that first synthesized
an element got the privilege of naming it.
In a new naming policy was adopted to
settle a conflict around element 104.
Americans wanted to name it rutherfordium,
while the Russians wanted to name it
kurchatovium.
IUPAC settled the matter by calling it
unnilquadium (un = 1, nil = 0, quad = 4)
In 1994, IUPAC relented, and element 104 was
renamed dubnium (Db), after Dubna, Russia.
Progression of scientific thought 18

39. New Element 112 (Ununbium)

40. Pivotal
Unk
1869
New 2009

41. THE END

42. The Backstory
In his 1811 paper Avogadro discusses Gay-Lussac's gas law and Dalton’s atomic theory. He calculates from gas densities that the molecular weight of nitrogen is times the molecular weight of hydrogen. Avogadro was the first to propose that the gaseous elements, hydrogen, oxygen, and nitrogen, are diatomic molecules. He deduced that the molecule of water contains a molecule of oxygen and two molecules of hydrogen. Dalton, who had assumed earlier that water is formed from a molecule each of oxygen and hydrogen, rejected Avogadro's and Gay-Lussac's laws.
There are no testimonials that Avogadro ever speculated on the number of molecules in a given gas volume and his law went for a long time largely unnoticed, not in the least because it was not recognized that the law holds strictly only for ideal gases, which many dissociating and associating organic compounds are not. Four years after Avogadro's death, at the historic (1860) chemistry conference in Karlsruhe, his countryman Stanislao Cannizaro explained why the exceptions to Avogadro's law happen and that it can determine molar masses.

43. Only through studies by Charles Frédéric Gerhardt and Auguste Laurent on organic chemistry was it possible to demonstrate that Avogadro's law explained why the same quantities of molecules in a gas have the same volume.
Unfortunately, related experiments with some inorganic substances showed seeming exceptions to the law. This was finally resolved by Stanislao Cannizzaro, as announced at Karlsruhe Congress in 1860, four years after Avogadro's death. He explained that these exceptions were due to molecular dissociations at certain temperatures, and that Avogadro's law determined not only molecular masses, but atomic masses as well.

44. On February 14, 1869, Mendeleev began work on the chapter that would discuss the elements. He already believed that there was some underlying principle connecting the elements. He transcribed his notes onto a set of cards, one for each element containing everything he knew about that element. He arranged and rearranged the cards until he was struck by a similarity between his arrangements and those of the card game patience (solitaire), in which cards are sorted by suit and then in descending numerical order. Exhausted, Mendeleev fell asleep. When he awoke, he devised a grouping of the elements by common property in ascending order of atomic weight. He called his innovation the Periodic Table of the Elements.
Within weeks, Mendeleev's Periodic Table was presented to the Russian Chemical Society and was published in the Journal of Russian Physical Chemistry; it was published later the same year in the prestigious German journal Zeitschrift für Chemie. Revised and expanded tables appeared in the Annalen der Chemie in Since the German journals were known to every research chemist, Mendeleev's Periodic Table became widely known almost at once. Although details of the tables were subject to argument, and many newly discovered elements were later added, the basic principle of organization behind the table was quickly accepted.

45. The true insight that informed Mendeleev's work was shown not just in what he had included in the Periodic Table, but also in what he had left out. He did not assume that all elements were known. Where there was a significant gap in atomic weights between the elements in the table, he left a gap in the table. He posited that there were undiscovered elements that existed in the gaps and even predicted the characteristics of three of them. He called these eka boron, eka aluminum, and eka silicon (eka being Sanskrit for "first"). See Tables 1 through 3 for the properties of these elements.
When these elements were eventually discovered, and because his system agreed with one developed independently by the German chemist Lothar Meyer in 1864, Mendeleev achieved widespread fame. The Periodic Table of the Elements provided a unifying system for classifying and understanding the elements and their function in the composition of matter.