Chemistry - CHEMICAL BONDING Question with Solution | TestHub

First ionization energy of Lead $=715\mathrm{kJ}{\mathrm{mol}}^{-1}$ First ionization energy of Tin $=708\mathrm{kJ}{\mathrm{mol}}^{-1}$ $\left({\mathrm{IE}}_1\right)$ of Lead is greater than that of Tin due to ineffective shielding of d - and f -electrons. Therefore Statement-I is true. First ionization energy of Germanium $=761\mathrm{kJ}{\mathrm{mol}}^{-1}$ First ionization energy of Silicon $=786\mathrm{kJ}{\mathrm{mol}}^{-1}$ $\left({\mathrm{IE}}_1\right)$ of Germanium is lower than that of Silicon as the effect of higher atomic radius of Ge outweighs the increase in nuclear charge from Si to Ge and effective shielding of inner electrons. Therefore Statement-II is false.