The nuclei having the same number of protons but different number of neutrons are called

The nuclear volume of $\frac{8}{4}\backslash frac\{8\}\{4\}$ Be is ………. that of $\frac{1}{1}\backslash frac\{1\}\{1\}$ H.

When a $\beta -particle\backslash beta\; -particle$ is emitted by a nucleus, its mass number

When an $\alpha -particle\backslash alpha-particle$ is emitted by a nucleus, its mass number

When a $\gamma -ray\backslash gamma-ray$ photon is emitted by an unstable nucleus,

In a radioactive transformation, a change in the mass number occurs with

The half-life of radium is 1600 y. How much of 1 μg of radium will remain undistintegrated after 8000 y?

In one mean lifetime of a radioactive element, the fraction of the nuclei that has disintegrated is [e is the base of natral logarithm.]

The decay constant of a radioactive element is $\lambda \backslash lambda$ After a time $2{\lambda }^{-1}2\; \backslash lambda\; ^\{-1\}$ of the original number of radioactive nuclei about ……………….. remains undecayed.

The energy generated in the stars is because of