fission reaction

Syllable breakdown

Dictionary meaning

A nuclear process in which the nucleus of a heavy atom (typically uranium-235 or plutonium-239) splits into two or more smaller nuclei upon absorption of a neutron, releasing a large quantity of energy and additional neutrons that can trigger further fissions in a chain reaction

History and origin

Latin fissio (splitting); fission as a term applied to nuclei was proposed by Lise Meitner and Otto Frisch in 1939 after Otto Hahn and Fritz Strassmann's experimental discovery

Examples

• A single fission reaction releases approximately 200 MeV of energy — roughly 50 million times more than burning one atom of carbon.
• Controlled fission reactions in nuclear power plants produce about 10% of global electricity.

Synonyms: nuclear fission, atomic splitting