Beta decay is a nuclear process in which a neutron changes into a proton, an electron, and a neutral particle called a neutrino, n+p+e+ū, where is the symbol for an antineutrino. When this change happens to a neutron within the nucleus of an atom, the proton remains behind in the nucleus while the electron and neutrino are ejected from the nucleus. The ejected electron is often referred to as a beta particle. One nucleus that exhibits beta decay is the isotope of hydrogen ³H, called tritium, whose nucleus consists of one proton and two neutrons. Tritium is radioactive, and it decays to helium, ³H ³He+ e + v.

Beta decay is a nuclear process in which a neutron changes into a proton, an electron, and a neutral particle called a neutrino, n+p+e+ū, where is the symbol for an antineutrino. When this change happens to a neutron within the nucleus of an atom, the proton remains behind in the nucleus while the electron and neutrino are ejected from the nucleus. The ejected electron is often referred to as a beta particle. One nucleus that exhibits beta decay is the isotope of hydrogen ³H, called tritium, whose nucleus consists of one proton and two neutrons. Tritium is radioactive, and it decays to helium, ³H ³He+ e + v.