A type of radioactive decay during which a beta particle is released from the atom nucleus. The beta particle could be an electron (we speak about beta minus decay) or a positron (an antielectron with a positive charge). This process is called beta plus decay. In the beta minus decay the neutron in the nucleus transforms into a proton, releasing an electron and electron antineutrino. The resulting nucleus has a more stable ratio between protons and neutrons. The beta plus decay also leads to the more stable nucleus. During the decay the proton is transformed into a neutron, and a positron and an electron neutrino are released. The beta radiation particles can be stopped by a thin metal sheet or by a few centimetres of water.