The atomic mass of ${ }_{6} C^{12}$ is $12.000000 \ u$ and that of ${ }_{6} C^{13}$ is $13.003354 \ u$. The required energy to remove a neutron from ${ }_{6} C^{13}$,if the mass of a neutron is $1.008665 \ u$,will be: (in $MeV$)

What is mass defect? Write down its formula.

The binding energy per nucleon of $^{16}O$ is $7.97 \ \text{MeV}$ and that of $^{17}O$ is $7.75 \ \text{MeV}$. The energy (in $\text{MeV}$) required to remove a neutron from $^{17}O$ is:

Deuteron is a bound state of a neutron and a proton with a binding energy $B = 2.2 \, MeV$. $A$ $\gamma$-ray of energy $E$ is aimed at a deuteron nucleus to try to break it into a (neutron + proton) such that the $n$ and $p$ move in the direction of the incident $\gamma$-ray. If $E = B$,show that this cannot happen. Hence,calculate how much bigger than $B$ must $E$ be for such a process to happen.

Draw the nature of the graph of average binding energy per nucleon against atomic mass number and explain its notable points.

The binding energy of a nucleus is a measure of its