Discuss abnormal behaviour of oxygen.

Explanation

Abnormal Behaviour of Oxygen : Oxygen differ from other members of its group (Group 16) in the following ways:
(i) Oxygen generally shows only one oxidation state of -2 while other element various other oxidation states such a +2, +4 and +6.
(ii) Molecular oxygen is paramagentic while other elements are diamagnetic.
(iii) Oxygen shows maximum covalency of two while other elements such as sulphur exhibit maximum convalency of six.
(iv) Oxygen is a gas while other members of the group are solid at room temperature.
(v) Oxygen can form hydrogen bonds while other elements of this group cannot do so.
Cause of abnormal behaviour of oxygen

(i) It has small size
(ii) It has high electronegativity
(ii) It has high ionisation enthalpy
(iv) It does not have d-orbitals in the valence shell.