Amongst the following ions which one has the highest magnetic moment value?
(i). `[Cr(H_2O)_6]^(3+)`
(ii). `[Fe(H_2O)_6]^(2+)`
(iii). `[Zn(H_2O)_6)]^(2+)`

Explanation

(ii). `Cr^(3+)=3d^(3)` unpaired electrons `=3`
`Fe^(2+)=3d^(6)`, unpaired electrons `=4`
`Zn^(2+)=3d^(10)`, unpaired electrons`=0`
Hence (ii) highest magnetic moment.