The binding energy per nucleon for a deuteron and an $\alpha$-particle are $x_1$ and $x_2$ respectively. The energy $Q$ released in the following reaction is:
$_1H^2 + _1H^2 \rightarrow {_2}{He}^4 + Q$

Calculate the energy equivalent of $1\; g$ of substance.

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.

As the mass number increases, the binding energy per nucleon .....

The energy equivalent of $1.0 \text{ kg}$ of substance is . . . . . . .

Binding energy of a nucleus is