|Example of gamma radioactivity|
Gamma radioactivity takes place when decay, or an event like a neutron capture, has left the nucleus with an energy surplus. The ‘excited’ nucleus generally returns to its ground state very quickly. The figure above shows a deformed nucleus rotating about an axis before returning to its spherical shape and losing its rotation momentum through the emission of a gamma ray. The gamma rays are of the same nature as those photons that form the light emitted by atoms, but have energies several hundred thousands of times greater.