Nickel (Z = 28) combines with a uninegative monodentate ligand `X^(-)` to form a paramagnetic complex `[NiX_4]^(2-)` . The number of unpaired electrons in the nickel and geometry of this complex ion are, respectively

Options

A. one, tetrahedral
B. two, tetrahedral Cone,
C. square planar
D. two, square planar

Answer

B

Explanation

The outer shell electronic configuration of Ni(28) is `3s^2 3p^6 3d^8 4s^2` and `Ni^(2+)` is `3s^2 3p^6 3d^8`. For a paramagnetic complex no pairing of 3d electrons would occur. Therefore, hybridization involved is `sp^3`, that is, tetrahedral shape.