Nickel $(Z=28)$ combines with a uninegative monodentate ligand $\mathrm{X}^{-}$to form a paramagnetic…
Nickel $(Z=28)$ combines with a uninegative monodentate ligand $\mathrm{X}^{-}$to form a paramagnetic complex $\left[\mathrm{NiX}_4\right]^{2-}$. The number of unpaired electron(s) in the nickel and geometry of this complex ion are, respectively