Which of the following transition metal ions has least magnetic moments?

Options

A. `Co^(3+)`
B. `Fe^(3+)`
C. `Cr^(2+)`
D. `V^(3+)`.

Answer

D

Explanation

1. Valence shell electron configuration off `Co^(3+)` is `3d^(6)4s^(0)`. So has 4 unpaired electrons.
2. Valence shell electron configuratoin of `Fe^(3+)` is `3d^(5)4s^(0)`. So has 5 unpaired electrons.
3. Valence shell electron configuration of `Cr^(2+)` is `3d^(4)4s^(0)`. so has 4 unparied electrons.
4. Valence shell electron configuration of `V^(3+)` is `3d^(2)4s^(0)`. so has 2 unpaired electrons it has least number of unpaired electrons, so it has least magnetic moment.