Question

For ${}_6{C}^{14}$, mass of proton is $a$, mass of neutron is $b$ and B.E is $X$. Find the mass of a nucleus of ${}_6{C}^{14}$ ($C$ = speed of light in vacuum)

• A. $6a+14b-\frac{X}{C^2}$
• B. $6a+8b+\frac{X}{C^2}$
• C. $6a+8b-\frac{X}{C^2}$
• D. $6a+14b+\frac{X}{C^2}$

Answer 1

The correct option is C $6a+8b-\frac{X}{C^2}$

We know binding energy is given by
$B.E=\Delta m.C^2$
where $\Delta m$ is the mass defect
$B.E.=\left\{\right(\text{Mass of constituents})-\left(\text{Mass of nucleus}\right)\}{C}^2$
$\frac{X}{C^2}=6a+8b-M_N$
$M_N=6a+8b-\frac{X}{C^2}$