First ionization energy of Lead =715 kJ mol−1 First ionization energy of Tin =708 kJ mol−1 (IE1) 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 kJ mol−1 First ionization energy of Silicon =786 kJ mol−1 (IE1) 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.