What Is Beta Emission?

When any nucleus emits an electron or a positron, the decay is called beta decay. It is also known as beta emission. When any nucleus emits a positron, it is said to undergo Beta⁺ decay. Beta positive decay is possible according to a theory called "proton-decay theory". According to it, inside a nucleus a proton decays into a neutron, positron and anti-neutrino. When any nucleus emits an electron it is said to undergo beta-negative decay. Beta negative decay is possible according to the theory called "neutron decay theory". According to it, inside a  nucleus, neutron decays into proton, electron and neutrino.