"gamma decay." YourDictionary, n.d. Web. 19 December 2018. <https://www.yourdictionary.com/gamma-decay>.
gamma decay. (n.d.). Retrieved December 19th, 2018, 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.