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

Hydrogen can be fused to form helium at

During the emission of a positron from a nucleus, the mass number of the daughter element remains the same but the atomic number

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:

When a radioactive substance is subjected to vacuum,the rate of disintegration per second

If the binding energy per nucleon of $_1H^2$ is $x$ and that of $_2He^4$ is $7x$,then the ratio of the energy liberated in the reaction $_1H^2 + _1H^2 \to _2He^4$ to the binding energy per nucleon of $_1H^2$ is: