"gamma decay." YourDictionary, n.d. Web. 14 January 2019. <https://www.yourdictionary.com/gamma-decay>.
gamma decay. (n.d.). Retrieved January 14th, 2019, from https://www.yourdictionary.com/gamma-decay
A radioactive process in which an atomic nucleus loses energy by emitting a gamma ray (a stream of high-energy photons). When an element undergoes gamma decay its atomic number and mass number do not change.