What is mass defect? the difference between the mass of the protons and the mass of the neutrons in an atom the difference between the mass of the nucleus in an atom and the total mass of individual nucleons the difference between the mass of the nucleus of an atom before and after a nuclear reaction

Mass defect is the difference between the mass of the nucleus in an atom and the total mass of individual nucleons.

Mass defect is defined as the difference of mass of nucleus to the sum of masses of proton and neutron.

The mass defect is given by the formula

Δm = (mn + mp) - mo

Here, (mn+mp) - represent combined mass of proton and neutron and mo - denotes original mass of atom