Hie-Joon Kim. Professor Emeritus Seoul National University. Experience. Representative Publications

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1 Hie-Joon Kim Professor Emeritus Seoul National University B.S. Chemistry, Seoul National University, Korea, 1970 Ph.D. Chemistry, University of Chicago, USA, 1977 Experience Professor, Department of Chemistry Seoul National University ( ) Chair Professor, Gwangju Institute of Science and Technology (2013-Present) SNU Teaching Award (2007) Representative Publications Philosophical Questions Scientific Answers (Thinking Power Books, 2012) Chemistry of Life, Chemistry for Life (Free Academy, 2009)

2 Chapter 4 Periodic Table

3 INTRODUCTION piano keys octave periodic table

4 INTRODUCTION Nobel Lecture in Physics (1904) The Density of Gases in the Air and the Discovery of Argon Lord Rayleigh ( )

5 4-1 Prout's Hypothesis In 1882 in an address to the British Association I suggested that the time had come for a redetermination of the gas densities, being interested in the question of Prout s law. William Prout

4-1 Prout's Hypothesis At that time the best results were those of Regnault, according to whom the density of oxygen was 15.

6 4-1 Prout's Hypothesis At that time the best results were those of Regnault, according to whom the density of oxygen was times that of hydrogen. The deviation of this number from the integer 16 seemed not to be outside the limits of experimental error. Dalton's atomic weight

7 4-2 Density of Nitrogen Air bubbled through liquid ammonia is passed through a tube containing copper at a red heat where the oxygen of the air is consumed by the hydrogen of the ammonia, the excess of the ammonia being subsequently removed with sulfuric acid.

8 4-2 Density of Nitrogen 78N O 2 + Ar + 28NH 3 = 92N 2 + Ar + 42H 2 O molecular weight = [(92)(28) + 40]/93 = 28.13

9 4-2 Density of Nitrogen Afterwards, I fell back upon the more orthodox procedure according to which, ammonia being dispensed with, air passes directly over red hot copper.

10 4-2 Density of Nitrogen Again a series in good agreement with itself resulted, but to my surprise and disgust the density obtained by the two methods differed by a thousandth part a difference small in itself but entirely beyond the experimental errors. 78N O 2 + Ar + 42Cu = 78N 2 + Ar + 42CuO molecular weight = [(78)(28) + 40]/79 = ( ) / =

11 4-2 Density of Nitrogen The most promising course for magnifying the discrepancy appeared to be the substitution of oxygen for air in the ammonia method, so that all the nitrogen should in that case be derived from ammonia. 21O NH 3 = 14N H 2 O

12 4-2 Density of Nitrogen Success was at once attained, the nitrogen from the ammonia being now 1/200 part lighter than that from air, a difference upon which it was possible to work with satisfaction. ammonia nitrogen air nitrogen pure nitrogen 28 ( ) / 28 =

13 4-3 Discovery of Argon On the supposition that the air-derived gas was heavier than the chemical nitrogen on account of the existence in the atmosphere of an unknown ingredient, the next step was the isolation of this ingredient by absorption of Ramsay Nobel Prize in Chemistry (1904) nitrogen.

4-3 Discovery of Argon Two methods were available the first consisting in the oxidation of the nitrogen under the influence of electric sparks with absorption of the acid compounds by alkali; the

14 4-3 Discovery of Argon Two methods were available the first consisting in the oxidation of the nitrogen under the influence of electric sparks with absorption of the acid compounds by alkali; the other method was to absorb the nitrogen by means of magnesium at a full red heat. 78N 2 + Ar + 234Mg = Ar + 78Mg 3 N 2 78N 2 + Ar + 234Cu = 78N 2 + Ar + 234Cu (nitrogen does not react with copper)

15 4-3 Discovery of Argon In both these ways a gas was isolated of amount equal to about one per cent of the atmosphere by volume and having a density about half as great again as that of nitrogen. Air argon

4-3 Discovery of Argon From the manner of its preparation it was proved to be nonoxidizable and to refuse absorption by magnesium at a red heat, and further

16 4-3 Discovery of Argon From the manner of its preparation it was proved to be nonoxidizable and to refuse absorption by magnesium at a red heat, and further varied attempts to induce chemical combination were without result. On this account the name argon was given to it. a- not -rg argon energy unreactive element

Grove battery, I was able to show the characteristic

17 4-3 Discovery of Argon By the use of a specially shaped tube and an ordinary induction-coil actuated by a small Grove battery, I was able to show the characteristic spectrum of argon at atmospheric pressure, starting with 5 cc only of air.

18 4-4 Periodic Table In subsequent investigations Ramsay and Travers discovered small quantities of new gases contained in the aggregate at first named argon. Helium, originally obtained by Ramsay from clevite, is also present in minute quantity. helium neon argon krypton xenon sun new lazy secret stranger

19 4-4 Periodic Table Discovery of Argon A New Element A New Group Chemical Bonding

20 Review To make water in the rain And starch in the grain The number of electrons the atoms compare. Then the electrons gladly they share Until they meet the octet rule That all students learn at school.

21 Nobel Lectures in Science THANK YOU

Hie-Joon Kim. Professor Emeritus Seoul National University. Experience. Representative Publications

Hie-Joon Kim. Professor Emeritus Seoul National University. Experience. Representative Publications Hie-Joon Kim Professor Emeritus Seoul National University B.S. Chemistry, Seoul National University, Korea, 1970 Ph.D. Chemistry, University of Chicago, USA, 1977 Experience Professor, Department of Chemistry