The graph of binding energy per nucleon $B_N$ versus mass number $A$ is given. In which process will energy be released?

The binding energy per nucleon is maximum in the case of

Binding energy per nucleon of ${ }_1^2 H$ and ${ }_2^4 He$ are $1.1 \ MeV$ and $7.0 \ MeV$ respectively. Energy released in the process ${ }_1^2 H + { }_1^2 H \rightarrow { }_2^4 He$ is: (in $MeV$)

Obtain the binding energy of the nuclei $^{56}_{26} Fe$ and $^{209}_{83} Bi$ in units of $MeV$ from the following data:
$m(^{56}_{26} Fe) = 55.934939 \; u$
$m(^{209}_{83} Bi) = 208.980388 \; u$ (in $; MeV$)

$A$ plot of the number of neutrons $(N)$ against the number of protons $(Z)$ for stable nuclei exhibits upward deviation from linearity for atomic number $Z > 20$. For an unstable nucleus having an $N/Z$ ratio less than $1$,the possible mode$(s)$ of decay is(are):
$(A)$ $\beta^{-}$-decay ($\beta$ emission)
$(B)$ Orbital or $K$-electron capture
$(C)$ Neutron emission
$(D)$ $\beta^{+}$-decay (positron emission)

$A$ radioactive nucleus has specific binding energy $E_{1}$. It emits an $\alpha$-particle. The resulting nucleus has specific binding energy $E_{2}$. Then