Of the ions `Zn^(2), Ni^(2 +)` and `Cr^(3 +)` [atomic number of `Zn = 30, Ni = 28, Cr = 24`]

Options

A. Only `Ni^(2+)` is coloured and `Zn^(2+)` and `Cr^(3+)` are colourless
B. All three are colourless
C. All three are coloured
D. Only `Zn^(2+)` is colourless and `Ni^(2+)` and `Cr^(3+)` are coloured

Answer

D

Explanation

`Ni^(2 +)` and `Cr^(3 +)` are coloured. But `Zn^(2 +)` is colourless because of absence of unpaired `e^(-2)`