Question

Colour in transition metal compounds is attributed to :

• A. small size of metal ions
• B. absorption of light in UV region
• C. complete $\left(ns\right)$ subshell
• D. incomplete $(n-1)d$ subshell

Answer 1

The correct option is D incomplete $(n-1)d$ subshell

Any compound or ion showing colour is due to presence of unpaired electron.
Transition metal compounds have incomplete (n-1)d sub shell and because of that they have unpaired electron and thus they show colour.