Found 2 items, similar to alpha particle.
English → English (WordNet) Definition: alpha particle alpha particle n : a positively charged particle that is the nucleus of the helium atom; emitted from natural or radioactive isotopes
English → English (gcide) Definition: alpha particle alpha particle \alpha particle\ (Physics & Chem.) a particle emitted at high velocity from certain radioactive substances. It is identical to the helium nucleus, consisting of two protons and two neutrons. Rays of such particles are called alpha rays. [Webster 1913 Suppl. +PJC]