Which of the following ions exhibits d-d transitions and paramagnetism as well?

Options

A. `MnO_(4)^(-)`
B. `Cr_(2)O_(7)^(2-)`
C. `CrO_(4)^(2-)`
D. `MnO_(4)^(2-)`

Answer

D

Explanation

`CrO_(4)^(2-) implies Cr^(6+)=[Ar]`
Unpaired electron (n)=0, Diamagnetic
`Cr_(2)O_(7)^(2-) implies Cr^(6+)=[Ar]`
Unpaired electron (n)=0, Diamagnetic `MnO_(4)^(2-)=Mn^(6+)=[Ar]3d^(1)`
Unpaired electron (n)=1, Paramagnetic `MnO_(4)^(-)=Mn^(7+)=[Ar]`
Unpaired electron (n)=0, Diamagnetic