The explosion of the atomic bomb takes place due to

In the process of a nuclear explosion,in which form is the maximum energy released?

$A$ nuclear reactor provides a power of $300 \, MW$. If the fission of one uranium nucleus ${U^{235}}$ releases $170 \, MeV$ of energy,how many nuclei undergo fission in $1 \, h$?

Nuclear fission experiments show that neutrons split uranium nuclei into two fragments of about the same size. This process is accompanied by the emission of several:

Assertion: Heavy water is a better moderator than normal water.
Reason: Heavy water absorbs neutrons more efficiently than normal water.

Suppose a ${ }_{88}^{226} Ra$ nucleus at rest and in the ground state undergoes $\alpha$-decay to a ${ }_{86}^{222} Rn$ nucleus in its excited state. The kinetic energy of the emitted $\alpha$ particle is found to be $4.44 \text{ MeV}$. The ${ }_{86}^{222} Rn$ nucleus then goes to its ground state by $\gamma$-decay. The energy of the emitted $\gamma$-photon is . . . . . . . $\text{keV}$.
[Given: atomic mass of ${ }_{88}^{226} Ra = 226.005 \text{ u}$,atomic mass of ${ }_{86}^{222} Rn = 222.000 \text{ u}$,atomic mass of $\alpha$ particle $= 4.000 \text{ u}$,$1 \text{ u} = 931 \text{ MeV}/c^2$]