It is normally emitted alongside alpha or beta radiation. Gamma radiation has no mass and no charge. It can be written as γ or \(_{0}^{0}\textrm{γ}\) An example of beta and gamma decay of cobalt ...

After emitting an alpha or beta particle, the nucleus will often still be ‘excited’ and will need to lose energy. It does this by emitting a high energy electromagnetic wave called a gamma ray.