Beta particle

A beta particle, also called beta ray or beta radiation (symbol β), is a high-energy, high-speed <a href="/facts/Electron/L0KBo5cW">electron</a> or <a href="/facts/Positron/HgV4zBzA">positron</a> emitted by the <a href="/facts/Radioactive_decay/Ya6FVjt4">radioactive decay</a> of an <a href="/facts/Atomic_nucleus/orpIm5Xl">atomic nucleus</a>, known as <a href="/facts/Beta_decay/vxTBlckp">beta decay</a>. 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; the distance is dependent on the particle's energy and the air's <a href="/facts/Density/92p6hh9I">density</a> and composition.
Beta particles are a type of <a href="/facts/Ionizing_radiation/vw0d9GaT">ionizing radiation</a>, and for <a href="/facts/Radiation_protection/5LaNNgXe">radiation protection</a> purposes, they are regarded as being more ionising than <a href="/facts/Gamma_ray/5Drf913J">gamma rays</a>, but less ionising than <a href="/facts/Alpha_particle/dzNMs9WP">alpha particles</a>. The higher the ionising effect, the greater the damage to living tissue, but also the lower the <a href="/facts/Mean_free_path/6M7eofRq">penetrating power</a> of the radiation through matter.

Beta particle open-in-new

Beta particle