Which of the following transition metal ion is not coloured?

Options

A. `Cu^(+)`
B. `V^(3+)`
C. `Co^(2+)`
D. `Ni^(2+)`

Answer

A

Explanation

Presence of unpaired electron is a necessity for transition metal ions to give colour. The electronic configuration of given transition metal ions are as
`"_(29)Cu^(+) = [Ar]3d^(10), 4s^(0)` (no unpaired electron)