Question

Transition metal compounds are usually coloured. This is due to the electronic transition :

• A. from p-orbital to s-orbital.
• B. from d-orbital to s-orbitals
• C. from p-orbital to p-orbital.
• D. d-d transition

Answer 1

The correct option is D d-d transition

Coloured compound of transition elements is associated with partially filled (n-1)d orbitals. the transition metal ions containing unpaired d-electrons undergoes electonic transition from one d-orbital to another.

During this d-d transition process the electrons absorb certain energy from the radiation and emit the remainder of energy as coloured light. The colour of ion is complementary of the colour adsorbed by it. Hence, coloured ion is formed due to d-d transition which falls in visible region for all transition elements.