How are beta rays related to electrons?

Beta rays, or beta particles, are fundamentally related to electrons through the process of beta decay, a form of radioactive disintegration.1

In negative beta decay, an unstable atomic nucleus emits an energetic electron along with an antineutrino. These emitted electrons are referred to as beta particles. It is important to note that these electrons originate from within the nucleus—where a neutron transforms into a proton—and are distinct from the orbital electrons that surround the nucleus.21

Beta decay can also involve positrons, which are particles identical to electrons in mass but possess a positive charge. In positron emission, a proton in the nucleus decays into a neutron, emitting a positron and a neutrino. Additionally, in electron capture, an atom may capture an inner-shell orbital electron into the nucleus to transform a proton into a neutron.1