Experimental physicist — James Franck (Hamburg 1882 – Göttingen 1964) was a German-born, naturalised American physicist. Together with Gustav Hertz, he carried out in 1914 the celebrated experiment that experimentally demonstrated the quantisation of atomic energy levels, directly confirming Bohr’s atomic model. For this work the two received the Nobel Prize in Physics in 1925. Of Jewish origin, he left Nazi Germany in 1933 and continued his career in the United States. During the Manhattan Project he promoted the “Franck Report”, in which the scientists called for the atomic bomb to be shown in a demonstration rather than used on cities.
Trivia
To keep the gold Nobel medals out of Nazi hands, the chemist Georg de Hevesy dissolved Franck’s and von Laue’s medals in aqua regia; the gold was later recovered and the medals recast after the war.
Theories and contributions
- Franck–Hertz experiment — Electrons transfer energy to atoms only in discrete amounts, demonstrating quantised energy levels: .
Featured in chapters
Linked atoms
2 linked atoms.