Joseph John Thomson

Born: 18 December 1856, Cheetham Hill, near Manchester, United Kingdom

Died: 30 August 1940, Cambridge, United Kingdom

Affiliation at the time of the award: University of Cambridge, Cambridge, United Kingdom

Prize motivation: “in recognition of the great merits of his theoretical and experimental investigations on the conduction of electricity by gases”

Field: Atomic physics
Experiments with Gases

The idea that electricity was transmitted by a charged smallest unit related to the atom was put forward in the 1830s. In the 1890s J.J. Thomson made experiments with charged particles in gases and managed to estimate its magnitude. In 1897 he showed that cathode rays, radiation emitted in a low pressure glass tube when a voltage is applied between two metal plates, consist of particles, electrons, that carry electricity. Thomson also concluded that electrons were part of the atom.