Definitions for "Beta particles"
high-speed electrons or positrons, especially those emitted in radioactive decay.
High-energy electrons released by radioactive decay.
Beta particle is a charged particle emitted from a radioactive atomic nucleus either natural or manufactured. The energies of beta particles range from 0 to 4 MeV. They carry a single charge; if this is negative, the particle is identical with an electron; if positive, it is a positron. An unstable atomic nucleus changes into a nucleus of the same mass number but different proton number with the emission of an electron and an antineutrino (or a positron and a neutrino)