Nuclei - Result Question 32
33. If $M(A ; Z), M_p$ and $M_n$ denote the masses of the nucleus $ _Z^{A} X$, proton and neutron respectively in units of $u(1 u=931.5 MeV / c^{2})$ and $BE$ represents its bonding energy in $MeV$, then
[2008] (a) $M(A, Z)=ZM_p+(A-Z) M_n-BE / c^{2}$
(b) $M(A, Z)=ZM_p^{p}+(A-Z) M_n+BE$
(c) $M(A, Z)=ZM_p^{p}+(A-Z) M_n-BE$
(d) $M(A, Z)=ZM_p^{p}+(A-Z) M_n+BE / c^{2}$
Show Answer
Answer:
Correct Answer: 33. (a)
Solution:
- (a) Mass defect $=ZM_p+(A-Z) M_n-M(A, Z)$
or, $\frac{B . E}{c^{2}}=Z M_p+(A-Z) M_n-M(A, Z)$
$\therefore \quad M(A, Z)=Z M_p+(A-Z) M_n-\frac{B . E \text{. }}{c^{2}}$
