Question

Oxygen is divalent, but sulphur exhibits variable valency of $2,4$ and $6$ because:

• A. sulphur is less electronegative than oxygen
• B. sulphur is bigger atom than oxygen
• C. ionisation potential of sulphur is more than oxygen
• D. of the presence of $d$-orbitals in sulphur

Answer 1

The correct option is D of the presence of $d$-orbitals in sulphur

Oxygen is divalent, but sulphur exhibits variable valency of 2, 4 and 6 because of the presence of $d$-orbitals in sulphur.

In sulphur, the excitation of $np$-electrons to $nd$-sub-shell gives rise to increase in number of unpaired electrons.

Option D is correct.