William Draper Harkins

Signature of William Draper Harkins

William Draper Harkins (born December 28, 1873 in Titusville , Pennsylvania , † March 7, 1951 in Chicago , Illinois ) was an American chemist ( physical chemistry , nuclear physics ).

Life

William Harkins went to school in Escondido ( California ) and studied chemistry at Stanford University from 1896 with a bachelor's degree in 1900. He then taught chemistry as a professor at the University of Montana in Missoula , but also continued his studies. In 1901 and 1904 he studied in Chicago and in 1905/06 in Stanford, where he received his doctorate in 1907/8 under Robert Eccles Swain . In 1909 he was in Germany with Fritz Haber in Karlsruhe, 1909/10 at the Massachusetts Institute of Technology (with Arthur Amos Noyes and Gilbert Newton Lewis , where he dealt with the thermodynamics of solutions) and in 1911 at the Carnegie Institution in Washington, DC left in 1912 he attended the University of Montana (where he worked for agriculture, forensic medicine and mining companies, among others) and taught at the University of Chicago . He was first assistant professor and from 1917 professor of physical chemistry. In 1939 he officially retired.

He has been a consulting chemist for both US government agencies and many companies. For example, he was on the National Defense Research Committee from 1941 to 1945 .

plant

Harkins studied surface chemistry (which began during his time as visiting professor at Fritz Haber, where he studied surface tension, and in Chicago he developed a theory of the orientation of molecules in surfaces) and was a pioneer in nuclear physics in the United States in the 1920s , at a time when physicists in the USA were hardly interested in it.

He first published in nuclear physics in 1915. Even then it was clear that the non-even numbers of the mean atomic weights were due to isotope effects. Harkins pursued this further and also considered the frequency of the elements (stability) under the aspect of the structure of nuclei from fundamental units (at that time protons and electrons were still suspected) and predicted the existence of the neutron early (like Ernest Rutherford ) (1920) , which was detected as a free particle in 1932 by James Chadwick . Harkins also introduced the word neutron in 1921. In his 1915 work he also speculated that the fusion of hydrogen to helium was the source of solar energy.

The Oddo-Harkins rule is named after him and Giuseppe Oddo (Oddo 1914, Harkins 1917), according to the frequency of the elements with increasing atomic number and increasing size and complexity of the nuclei and with neighboring nuclei those with an even atomic number are more common than those with odd.

He investigated the decay of nitrogen and other nuclei after bombardment with alpha particles (and neutrons) in cloud chambers . He assumed that a compound core formed briefly and then a nuclear fission set in. Shortly after developing the cyclotron , he built one with his students in Chicago (in Operation 1936). He also undertook experiments on isotope separation with diffusion for chlorine and mercury. He also developed ideas for the shell structure of the cores early on.

Honors and memberships

In 1928 he received the Willard Gibbs Medal . He was a member of the National Academy of Sciences since 1921 and of the American Philosophical Society since 1925 . He was vice president of the American Association for the Advancement of Science .

Private

In 1904 he married the English professor Anna Louis Hathaway and had two children (his daughter was a concert singer and his son Henry Harkins was a surgeon). Harkins was a passionate mountaineer.

Fonts

• Physical Chemistry of Surface Films, New York: Reinhold Publ. 1952

Some work on nuclear physics:

• with ED Wilson:
  • Energy relations involved in the formation of complex atoms, Phil. Mag. 30, 1915, 723
• The changes of mass and weight involved in the formation of complex atoms, J. Am. Chem. Soc. 37, 1915, 1367
  • The structure of complex atoms: the hydrogen and helium system, J. ACS, 37, 1915, 1383
  • Recent work on the structure of the atom, J. ACS, 37, 1915, 1396
  • The structure of complex atoms an the changes of mass and weight involved in their formation, Proc. Nat. Acad., 1, 1915, 276
• The abundance of elements in relation to the hydrogen-helium structure of atoms, Proc. Nat. Acad. Sci. 2, 1916, 216
• The nuclei of atoms and the new periodic system, Phys. Rev., 15, 1920, 73
• The stability of atoms as related to the positive and negative electrons in their nuclei and the hydrogen helium, H3, H2 theory of nuclear structure, J. ACS 42 1920, 1956
• Natural system of the classification of isotopes and the atomic weights of pure atomic species as related to nuclear stability, J. ACS 43, 1921, 1038
• The stability of atomic nuclei, the separation of isotopes and the whole number rule 1-5, Franklin Institute, Vol. 194, 1922, 165, 329, 531, 645, 783
• The atomic systems, which are accompanied by atomic fission (atomic shattering), and the theory of the structure of atoms from hydrogen and helium, Z. f. Physics, 50, 1928, 97
• The synthesis of atoms, the whole number rule, and the periodic system of atomic species, Chem. Rev. 5, 1928, 371
• Atomic stability as related to nuclear spin, Phys. Rev. 35, 1930, 434
• with DM Gans, HW Newson: Atomic disintegration by a relatively slow neutron, Phys. Rev. 43, 1933, 208 (and other work)
• The neutron, the atomic nucleus and mass defects, J. ACS 55, 1933, 855
• The neutron, atomic building and a nuclear exclusion principle, Proc. Nat. Acad., 19, 1933, 307
• Nuclear chemistry, the neutron and artificial radioactivity, Science 83, 1936, 533
• The intermediate nucleus in the disintegrative synthesis of atomic nuclei: disintegration in steps, Proc. Nat. Acad., 23, 1937, 120
• The neutron, the intermediate or compound nucleus and the atomic bomb, Science, 103, 1946, 289

Web links

• Biography at NAS, by Robert Mulliken, pdf

Individual evidence

1. ^ Biographical data, publications and academic family tree of William Draper Harkins at academictree.org, accessed February 8, 2018.
2. ↑ Independent of Irving Langmuir and the biologist WG Hardy
3. ↑ with ED Wilson
4. ↑ Who referred to Harkins in his 1920 Bakerian Lecture
5. ↑ Nils Wiberg (Ed.): Textbook of Inorganic Chemistry Textbook of Inorganic Chemistry. Walter de Gruyter 2007 (102nd edition). ISBN 9783110206845 . doi : 10.1515 / 9783110177701 p. 83
6. ↑ Oddo-Harkins Rule
7. ^ Harkins, CE Broeker The first separation of the chlorine isotopes , Z. f. Physics, 50, 1928, 537
8. ^ Harkins, Mortimer The separation of isotopes and a further separation of mercury by evaporite-diffusion , Phil. Mag., 6, 1928, 601
9. ^ Member History: William D. Harkins. American Philosophical Society, accessed September 21, 2018 .