Question

Covalency of oxygen cannot exceed 2, unlike sulphur which can show +4 or +6 because:

• A. oxygen atom does not have d-orbitals
• B. oxygen atom has two unpaired electrons in its valence shell
• C. oxygen can form a double bond with another oxygen atom
• D. electrons of oxygen atom cannot be promoted to d-orbitals due to its small size

Answer 1

The correct option is A oxygen atom does not have d-orbitals

Oxygen does not have a d-orbital thereby not exceeding its covalency beyond $2$. Whereas sulphur has vacant d-orbitals hence can exceed its covalency to $+4$ or $+6$.