Which is more destructive: an atomic bomb or a hydrogen bomb?

The binding energy of deuteron is $2.2 \, MeV$ and that of $_2^4He$ is $28 \, MeV$. If two deuterons are fused to form one $_2^4He$,then the energy released is ......... $MeV$.

$A$ nucleus of uranium decays at rest into nuclei of thorium and helium. Then:

If each fission in a $U^{235}$ nucleus releases $200 \, MeV$, how many fissions must occur per second to produce a power of $1 \, kW$?

In the proton-proton cycle in the Sun,the energy released when an electron and its antiparticle combine is $\qquad$ .

The energy released by the fission of one uranium atom is $200 MeV$. The number of fissions per second required to produce $3.2 W$ of power is (Take $1 eV = 1.6 \times 10^{-19} J$).