The mass of a nucleus $^{A}_{Z}X$ is $M$. If $m_p$ and $m_n$ are the masses of a free proton and a f

Question

The mass of a nucleus $^{A}_{Z}X$ is $M$. If $m_p$ and $m_n$ are the masses of a free proton and a free neutron respectively, the mass defect $\Delta M$ is given by:

Professor PC Thomas Classes · Answer

Mass defect is the difference between the sum of the masses of individual free nucleons and the actual mass of the bound nucleus: $\Delta M = [Z m_p + (A-Z) m_n] - M$.