Question

Oxygen generally exhibits an oxidation state of - 2 only whereas other members of its family show oxidation states of + 2, + 4 and + 6 as well. Explain why?

Answer 1

Dear Student,

The electronic configuration of oxygen is 1s² 2s² 2p_x² 2p_y¹ 2p_z¹ i.e., it has two half-filled orbitals and there is no d-orbital available for excitation of electrons. Further it is the most electronegative element of its family. Hence it shows oxidation state of -2 only. Other elements like sulphur have d-orbitals available for excitation thereby giving four and six half-filled orbitals. Moreover they can combine with more electronegative elements. Hence they show oxidation states of + 2, + 4 and + 6 also.

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