The density of neutrons is of the order

The mass of the proton is $1840$ times that of an electron. If a proton is accelerated through a potential difference of $1 \,kV$,the kinetic energy of the proton would be

The radius of the nucleus is related to the mass number $A$ by

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.

The increasing order (lowest first) for the values of $e/m$ (charge/mass) for:

An elementary particle is: