(i) The ionization energy decreases regularly down the group; Pb however shows a higher value than Sn due to poor shielding of inner f-orbitals as a result of which effective nuclear charge experienced by outer shell electrons becomes more in Pb.

(ii) The first ionization energies of group 14 elements are higher than their corresponding group 13 elements because of smaller size.

(iii) The electropositive character of these elements increases down the group because of decreases in ionization energy.

(i) Presence of four electrons in outermost shell of these elements reveals that the members of this family can gain four electrons forming M⁴⁺ or M^4- ions to show ionic nature or exhibit tetravalent covalent nature by sharing of four electron pairs in order to attain stable configuration.

(ii) The formation of M⁴⁺ or M^4- ions require huge amount of energy which is normally not available during normal course of reactions, therefore, these elements usually do not form M⁴⁺ or M^4- ions, but they usually form compounds with covalence of four.

(iii) Ge, Sn and Pb also exhibit +2 oxidation state due to inert pair effect.

(iv) Sn²⁺ and Pb²⁺ show ionic nature.

(v) The tendency to form +2 ionic state increases on moving down the group due to inert pair effect.