The explosive in a Hydrogen bomb is a mixture of $${ }_1 \mathrm{H}^2,{ }_1 \mathrm{H}^3$$ and $${ }_3 \mathrm{Li}^6$$ in some condensed form. The chain reaction is given by

$$\begin{aligned} & { }_3 \mathrm{Li}^6+{ }_0 \mathrm{n}^1 \rightarrow{ }_2 \mathrm{He}^4+{ }_1 \mathrm{H}^3 \\ & { }_1 \mathrm{H}^2+{ }_1 \mathrm{H}^3 \rightarrow{ }_2 \mathrm{He}^4+{ }_0 \mathrm{n}^1 \end{aligned}$$

During the explosion the energy released is approximately

[Given ; $$\mathrm{M}(\mathrm{Li})=6.01690 \mathrm{~amu}, \mathrm{M}\left({ }_1 \mathrm{H}^2\right)=2.01471 \mathrm{~amu}, \mathrm{M}\left({ }_2 \mathrm{He}^4\right)=4.00388$$ $$\mathrm{amu}$$, and $$1 \mathrm{~amu}=931.5 \mathrm{~MeV}]$$

The atomic mass of $${ }_6 \mathrm{C}^{12}$$ is $$12.000000 \mathrm{~u}$$ and that of $${ }_6 \mathrm{C}^{13}$$ is $$13.003354 \mathrm{~u}$$. The required energy to remove a neutron from $${ }_6 \mathrm{C}^{13}$$, if mass of neutron is $$1.008665 \mathrm{~u}$$, will be :

The radius of third stationary orbit of electron for Bohr's atom is R. The radius of fourth stationary orbit will be: