alpha particle

== English == === Pronunciation === === Noun === alpha particle (plural alpha particles) (physics) A doubly positively charged nucleus of a helium-4 atom (consisting of two protons and two neutrons), emitted as a consequence of radioactivity. Alternative form: α-particle Hypernyms: helion (broad sense, uncommonly) < ion < particle Holonyms: alpha ray, alpha radiation Coordinate terms: helion (usual sense, helium-3 ion); beta particle ==== Derived terms ==== ==== Translations ==== ==== See also ====