Write the electronic configuration of `Cr^(2+)` and find the number of unpaired electrons in it.

Explanation

For Cr (Z=24), the electronic configuration is `[Ar]3d^5 4s^1` and for `Cr^(2+)` the electronic configuration is `[Ar]3d^4` . Hence, the number of unpaired electrons in `Cr^(2+)` is four.