In the nuclear fission of one nucleus of $\mathrm{U}^{235}$ the energy released is 188 MeV . The energy released in the nuclear fission of 235 g of $\mathrm{U}^{235}$ is nearly

(Avogadro number $=6.02 \times 10^{23} \mathrm{~mol}^{-1}$ )

If $F_1$ and $F_2$ are the relative strengths of the gravitational and weak nuclear forces respectively, then $F_2 / F_1$ is nearly

In the following nuclear reaction $X$ is

$$ { }_{13} \mathrm{Al}^{27}+{ }_2 \mathrm{He}^4 \longrightarrow{ }_0 n^1+X $$