The chemical properties of an atom are determined by its valence electrons.

When an electron hits a $\mathrm{ZnS}$ screen, scintillation is produced.

The nature of anode rays depends upon the nature of residual gas.

The energy of an electron is negative.

The radius of the nucleus is of the order of ${10}^{-12} \mathrm{cm}$. 

The radius of an atom is of the order of ${10}^{-8} \mathrm{cm}$.