Physicist — Gustav Ludwig Hertz (Hamburg 1887 – Berlin 1975) was a German physicist, nephew of Heinrich Hertz, the discoverer of electromagnetic waves. Together with James Franck he carried out, in 1914, the celebrated experiment that directly demonstrated the quantisation of atomic energy levels, experimentally confirming Bohr’s model. By bombarding mercury atoms with electrons, the two showed that energy was absorbed only in discrete, well-defined amounts. For this work they shared the Nobel Prize in Physics in 1925. After the Second World War Hertz worked for several years in the Soviet Union, contributing to research programmes on isotope separation.

Theories and contributions

  • Franck-Hertz experiment — Electrons transfer energy to atoms only in discrete amounts, proving the quantisation of levels: E=hνE=h\nu.

Linked atoms

2 linked atoms.

21 Introduzione alla meccanica quantistica