The number of unpaired electrons in the complex ion [ CoF ₆ ]³⁻ is: (Atomic no. : Co =27 )

Step-by-step solution

( Co ( Z =27) ) has observed electronic configuration ([ Ar ] 3 ~d ^7 4 ~s ^2 . Co ³⁺ ) has electronic configuration ([ Ar ] 3 ~d ^6 4 ~s ^0 [ CoF ₆ ]³⁻ ) is a high spin complex and contains 4 unpaired electrons.