In which of the following paris both the ions are coloured in aqueous solution? (Atomic number, `Sc - 21, Ti = 22, Ni = 28, Cu = 29, Co = 27)`

Options

A. `Ni^(2+)` and `Cu^(+)`
B. `Sc^(3+)` and `Ti^(3+)`
C. `Sc^(3+)` and `Co^(2+)`
D. `Ni^(2+)` and `Ti^(3+)`

Answer

D

Explanation

`Ni^(2+)` and `Ti^(3+)` ions coloured in aqueous solution because they contain unpaired electrons.