Formation of a nucleus from its nucleons is accompanied by:

If the binding energy per nucleon of $_1H^2$ is $x$ and that of $_2He^4$ is $7x$,then the ratio of the energy liberated in the reaction $_1H^2 + _1H^2 \to _2He^4$ to the binding energy per nucleon of $_1H^2$ is:

${}_{90}Th^{232} \rightarrow {}_{82}Pb^{208}$. The number of $\alpha$ and $\beta$-particles emitted during the above reaction is:

The nucleus of a radioactive element possesses:

The measure of binding energy of a nucleus is the

The number of neutrons in the parent nucleus which gives $^{14}N$ on $\beta$-emission is