- The spontaneous change of an atomic nucleus accompanied by the emission of alpha, beta particles or gamma radiation.
- Alpha Decay
- Nuclear decay by emission of an alpha particle (4He nucleus).
- Beta Decay
- Nuclear decay by emission of an electron or a positron. Positron decay is always accompanied by electron capture decay.
- Gamma Rays
- Gamma ray emission is a decay mode by which the excited state of a nucleus de-excite to lower (more stable) state in the same nucleus.