How much energy is released when $1 \,g$ of hydrogen is converted into $0.993 \,g$ of helium?

The mass of a proton is $1.0073 \; u$ and that of a neutron is $1.0087 \; u$ ($u =$ atomic mass unit). The binding energy of ${ }_2^4 \text{He}$ is (Given: helium nucleus mass $\approx 4.0015 \; u$):

The mass of a $H$-atom is less than the sum of the masses of a proton and an electron. Why is this?

The binding energy of a nucleon in a nucleus is of the order of a few

The atomic mass of ${ }_7 N ^{15}$ is $15.000108 \text{ a.m.u.}$ and that of ${ }_8 O ^{16}$ is $15.994915 \text{ a.m.u.}$ If the mass of a proton is $1.007825 \text{ a.m.u.}$,then the minimum energy required to remove the least tightly bound proton is ......... $MeV$.

Assume that the nuclear binding energy per nucleon $(B/A)$ versus mass number $(A)$ is as shown in the figure. Use this plot to choose the correct choice$(s)$ given below.
Figure: $222706-q$
$(A)$ Fusion of two nuclei with mass numbers lying in the range of $1 < A < 50$ will release energy.
$(B)$ Fusion of two nuclei with mass numbers lying in the range of $51 < A < 100$ will release energy.
$(C)$ Fission of a nucleus lying in the mass range of $100 < A < 200$ will release energy when broken into two equal fragments.
$(D)$ Fission of a nucleus lying in the mass range of $200 < A < 260$ will release energy when broken into two equal fragments.