The fact that the atom is divisible was determined from ............ .

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 ......... .

$A$ particle having the same charge and $200$ times greater mass than that of an electron is:

The radius of an atom is about

The size of the nucleus is of the order of

Which of the following statements is incorrect regarding cathode rays?