Are neutrons present in all atomic nuclei? Explain.

Which particle cannot be accelerated?

Explain the discovery of the electron.

$A$ neutral atom (Atomic number $Z > 1$) consists of:

The nucleus of an atom can be assumed to be spherical. The radius of the nucleus of mass number $A$ is given by $1.25 \times 10^{-13} \times A^{1/3} \ cm$. The radius of the atom is $1 \ \mathring{A}$. If the mass number is $64$,then the fraction of the atomic volume that is occupied by the nucleus is:

Which of the following particles is represented by the symbol $\alpha$?