Alpha particles are $...$ times heavier (approximately) than neutrons.

An electron has mass $m$ and charge $e$. If it is accelerated from rest through a potential difference of $V$,what velocity will it attain?

How did Chadwick discover the neutron? Explain.

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

Fill in the blanks:
$(i)$ When amber or ebonite is rubbed with silk or fur,it produces $......$.
$(ii)$ In a discharge tube,the stream of particles flows from cathode to anode. This is called $......$.
$(iii)$ In a cathode ray tube,a coating of $......$ is applied as a fluorescent material.
$(iv)$ $A$ television picture tube is a type of $......$ tube.

Who discovered the neutron?