Question 184 of 239

The binding energy for the following nuclear reactions are expressed in MeV.
${ }_{2} \mathrm{He}^{3}+{ }_{0} \mathrm{n}^{1} \rightarrow{ }_{2} \mathrm{He}^{4}+20 \mathrm{MeV}$
${ }_{2} \mathrm{He}^{4}+{ }_{0} \mathrm{n}^{1} \rightarrow{ }_{2} \mathrm{He}^{5}-0.9 \mathrm{MeV}$
If $\mathrm{X}_{3}, \mathrm{X}_{4}, \mathrm{X}_{5}$ denote the stability of ${ }_{2} \mathrm{He}^{3},{ }_{2} \mathrm{He}^{4}$ and ${ }_{2} \mathrm{He}^{5}$, respectively, then the correct order is :