Which one of the following is an outer orbital complex and exhibits paramagnetic behaviour?

Options

A. `[Ni(NH_3)_6]^(2+)`
B. `[Zn(NH_3)_6]^(2+)`
C. `[Cr(NH_3)_6]^(3+)`
D. `[Co(NH_3)]^(3+)`

Answer

A

Explanation

`ln [ Ni(NH_3)_6]^(3-), Ni^(2+)" is " 3d^8`. Its electronic configuration is

Thus, hybridization is `sp^3d^2` giving outer orbital complex which is paramagnetic.