For the decay of a nucleus,which of the following is $NOT$ a possible reason?

The mass of ${ }_7 N ^{15}$ is $15.00011 \ amu$,the mass of ${ }_8 O ^{16}$ is $15.99492 \ amu$,and $m_p = 1.00783 \ amu$. Determine the binding energy of the last proton of ${ }_8 O ^{16}$ in $MeV$.

One atomic mass unit is equivalent to .............. $MeV$ energy.

If the binding energy of the deuterium is $2.23 \, MeV$, the mass defect in $a.m.u.$ is:

Find the energy equivalent of one atomic mass unit,first in $Joules$ and then in $MeV$. Using this,express the mass defect of $_{8}^{16} O$ in $MeV / c^{2}$.

Answer the following questions:
$(a)$ Are the equations of nuclear reactions 'balanced' in the sense a chemical equation (e.g.,$2H_2 + O_2 \rightarrow 2H_2O$) is? If not,in what sense are they balanced on both sides?
$(b)$ If both the number of protons and the number of neutrons are conserved in each nuclear reaction,in what way is mass converted into energy (or vice-versa) in a nuclear reaction?
$(c)$ $A$ general impression exists that mass-energy interconversion takes place only in nuclear reactions and never in chemical reactions. This is strictly speaking,incorrect. Explain.