How did Chadwick discover the neutron? Explain.

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.

What is the ratio of the mass of an electron to the mass of a proton?

Positronium is the name given to an atom-like combination formed between

Cathode rays are

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 ......... .