Mass Defect

Name:
Mass Defect
Detailed information:
The difference between the total mass of the constituents of an atomic nucleus (protons and neutrons) taken independently, and the actual mass of the nucleus as a whole. The latter is always slightly less than the sum of the masses of the constituents, the difference being the mass equivalent of the energy of formation (binding energy) of the nucleus. This accounts for the high energy release obtained from nuclear fission.See Fission; Mass Number.