Beta particle
Ionizing radiation
A beta particle, also called beta ray or beta radiation (symbol β), is a high-energy, high-speed electron or positron emitted by the radioactive decay of an atomic nucleus, known as beta decay. There are two forms of beta decay, β− decay and β+ decay, which produce electrons and positrons, respectively. Beta particles with an energy of 0.5 MeV have a range of about one metre in the air, and can't pass through clothing or thin metal sheets; the distance is dependent on the particle's energy and the air's density and composition.
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