Question

The colour of transition metal ions is due to ______ transitions.

Answer 1

The colour of transition metal ions is due to d-d transitions.

Explanation:

Transition metal ions have partially filled d-orbitals. When light falls on them, electrons get excited from one d-orbital to another; this is called a d-d transition. The energy absorbed during this transition corresponds to certain wavelengths of visible light, and the rest is reflected, giving the ion its characteristic colour.