What is a Beta Particle?
The beta particle is a form of ionizing radiation related to other common forms of radiation, alpha particles and gamma rays. The beta particle is a high-speed electron or positron released from a degenerating radioactive nucleus. Being medium-energy and low mass, beta particles are one of the least damaging forms of radiation, but still a very significant health concern. Beta emitters include strontium-90, potassium-40, technetium-99, tritium, and carbon-14. Beta particles have equivalent properties to electrons, but much higher energies than typical electrons orbiting the nucleus. Though beta particles are not themselves radioactive, they cause damage ballistically, breaking chemical bonds and creating ions which do damage to tissue. The cause of beta emission is an excess number of neutrons in the atomic nucleus. When there are significantly more neutrons than protons in a nucleus, the neutrons degenerate into protons and electrons, which are ejected from the nucleus at high speeds.
