Question

Why do transition metals show variable oxidation states?

Hint:

Variable oxidation state due to involvement of both ns and (n−1)d electrons.

Answer 1

Transition metals have partially filled \( (n-1)d \) orbitals along with outer \( ns \) electrons. Both \( ns \) and \( (n-1)d \) electrons can participate in bonding.
Reason:

• Small energy difference between \( ns \) and \( (n-1)d \) orbitals
• Electrons from both orbitals are used in bond formation

Hence, different numbers of electrons can be lost. \[ \therefore \text{Transition metals exhibit variable oxidation states. \]