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 in Escondido (California ) to school and studied chemistry in 1896 from Stanford University with a bachelor's degree in 1900. Afterwards he taught as a professor at the University of Montana in Missoula chemistry, but also continued his studies. 1901 and 1904 he studied in Chicago and 1905/ 06 at Stanford, where he received his doctorate in 1908. In 1909 he was in Germany at Fritz Haber in Karlsruhe, 1909/10 at the Massachusetts Institute of Technology ( Arthur Amos Noyes at and Gilbert Newton Lewis, he studied there with thermodynamics of solutions) and 1911 at the Carnegie Institution in Washington DC In 1912 he left the University of Montana ( where he worked for the agriculture, forensics and mining companies ) and taught at the University of Chicago. He was first an assistant professor and from 1917 Professor of Physical Chemistry. In 1939 he was officially retired.

He was a consulting chemist for both U.S. government agencies as well as for many companies. For example, he was from 1941 to 1945 in the National Defense Research Committee.

Work

Harkins was concerned (which began in his time as a visiting professor at Fritz Haber, where he dealt with surface tension, and in Chicago, he developed a theory of the orientation of molecules in surfaces) with surface chemistry and was in the 1920s, a pioneer of nuclear physics in the U.S., at a time when not many physicists in the United States for interested.

In nuclear physics, first published in 1915. It was clear at that time that the non -even numbers the average atomic weights were due to isotope effects. Harkins pursued further and also looked at the frequency of the elements ( stability) in terms of the structure of nuclei from fundamental units ( it was thought at that time protons and electrons) and said earlier (as well as Ernest Rutherford ) the existence of the neutron before ( 1920) which was detected as a free particle in 1932 by James Chadwick. Harkins also introduced in 1921 the word neutron one. In his work of 1915 he speculated about that also the fusion of hydrogen into helium was the source of solar energy.

According to him and Giuseppe Oddo is the Oddo - Harkins rule named ( Oddo 1914 Harkins 1917), decreases according to the frequency of the elements with increasing atomic number and increasing size and complexity of the nuclei and in neighboring nuclei are with even numbers more frequently than those with odd.

He examined the decay of nitrogen and other nuclei after bombardment with alpha particles ( and neutron) in cloud chambers. He assumed that briefly formed a compound nucleus and then began a nuclear fission. Shortly after the development of the cyclotron, he built one with his students in Chicago ( in operation 1936). He also undertook experiments on isotope separation by diffusion in chlorine and mercury. He also developed early ideas to the shell structure of the nuclei.

Honors and Memberships

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

Private

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

Writings

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

Some work on nuclear physics:

• E. D. Wilson: Energy relations Involved in the formation of complex atom, Phil Mag 30, 1915, 723

• The structure of complex atom: the hydrogen and helium system, J. ACS, 37, 1915, 1383
• Recent work on the structure of the atom, J. ACS, 37, 1915, 1396