The huge amount of energy which is released during atomic fission is due to

The atomic mass of an element is $12.00710 \, amu$. If there are $6$ neutrons in the nucleus of the atom of the element,the binding energy per nucleon of the nucleus will be $....... \, MeV$.
($e^{-} = 0.00055 \, amu$,$p = 1.00814 \, amu$,$n = 1.00893 \, amu$)

Stable nuclides are those whose $n/p$ ratio is

$_{13}^{27}Al$ is a stable isotope. $_{13}^{29}Al$ is expected to disintegrate by

Ordinary water is not used as a moderator in nuclear reactors because

Let $m_p$ be the mass of a proton,$m_n$ that of a neutron,$M_1$ that of a $_{10}^{20}Ne$ nucleus,and $M_2$ that of a $_{20}^{40}Ca$ nucleus. Then: