Identify the correct increasing order of $e/m$ ratio for the following particles: $n, p, e, \alpha$.

State whether the following statements are true or false:
$(i)$ Faraday's electrolysis experiments and cathode ray discharge tube experiments prove that protons are located in the nucleus of the atom,while electrons are located outside the nucleus.
$(ii)$ In the year $1887$,Goldstein discovered the proton.
$(iii)$ In the year $1932$,the neutron was discovered by Chadwick.
$(iv)$ The first atomic model was proposed by Thomson.

Rutherford's scattering experiment is related to the size of the

$(i)$ Calculate the number of electrons which will together weigh $1 \, g$.
$(ii)$ Calculate the mass and charge of one mole of electrons.

The radius of a nucleus with mass number $A$ is given by $1.25 \times 10^{-13} \times A^{1/3} \ cm$. If the radius of the atom is $1 \ \mathring{A}$ and the mass number is $64$,calculate the fraction of the volume occupied by the nucleus.

Fill in the blanks:
$(i)$ For the discovery of neutrons,$\alpha$-particles were bombarded on a thin sheet of ......... .
$(ii)$ For the $\alpha$-particle scattering experiment,Rutherford used a gold foil of thickness ......... .
$(iii)$ The radius of an atom is approximately ......... and the radius of the nucleus is ......... .
$(iv)$ The entire positive charge of an atom is concentrated in a very small region,which is called ......... .