Who discovered the proton and the neutron?

Which of the following pairs has the identical $e/m$ value?

The volume of an atom is $10^5$ times the volume of its nucleus. If we consider the ratio of the radius of an atom to the radius of its nucleus,it is approximately $10^5$. Since volume $V = \frac{4}{3} \pi r^3$,the ratio of volumes is $(\frac{r_{atom}}{r_{nucleus}})^3 = (10^5)^3 = 10^{15}$. Therefore,the volume of an atom is $10^{15}$ times the volume of the nucleus. Choose the correct factor.

The proton and neutron are collectively called as

Rutherford's experiment on scattering of $\alpha$-particles showed for the first time that the atom has:

Experimental evidence for the existence of the atomic nucleus comes from