Question

Square-planar $\left[Ni\right(CN{)}_4{]}^{2-}$ uses ...............$d-$orbital(s) (in number) in hybridization.

Answer 1

Square-planar $\left[Ni\right(CN{)}_4{]}^{2-}$ uses one $d-$orbital(s) in hybridization. The hybridization involved is $ds{p}^2$.