Q. $M_{p}$ denotes the mass of a proton and $M_{n}$ that of a neutron. A given nucleus, of binding energy $B$, contains $Z$ protons and $N$ neutrons. The mass $M(N,Z)$ of the nucleus is given by ($c$ is the velocity of light)
A) $M(N,Z) = NM_{n} + ZM_{p} - Bc^{2}$
B) $M(N,Z) = NM_{n} + ZM_{p} + Bc^{2}$
C) $M(N,Z) = NM_{n} + ZM_{p} - B/c^{2}$
D) $M(N,Z) = NM_{n} + ZM_{p} + B/c^{2}$
Explanation
(c) $B = \lbrack Z\ M_{p} + N\ M_{n} - M(N,Z)c^{2}$
$\Rightarrow M(M,Z) = ZM_{p} + NM_{n} - B/c^{2}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.