Among `[Ni(CO)_(4)], [NiCl_(4)]^(2-), [Co (NH_(3))_(4) Cl_(2)] Cl, Na_(3) [CoF_(6)], Na_(2)O_(2)` and `CsO_(2)`, the total number of paramagnetic compounds is

Options

A. 2
B. 3
C. 4
D. 5

Answer

B

Explanation

`{:(,,"Unpaired electrons"),([Ni(CO)_(4)],3d^(10)(sp^(3)),0),([NiCl_(4)]^(2-),3d^(8)(sp^(3)),2),([Co(NH_(3))_(4)Cl_(2)]Cl,3d^(6)(d^(2)sp^(3)),0),(Na_(3)[CoF_(6)],3d^(6)(sp^(3))d^(2),4),(Na_(2)O_(2),O_(2)^(2-),0),(CsO_(2),O_(2)^(-),1):}`