The metal $Ni$ $(Z = 28)$ combines with a unidentate ligand $X^-$ to form a paramagnetic complex $[NiX_4]^{2-}$. What are its geometry and the number of unpaired electrons in $Ni$?

Given below are two statements :
Statement $I$: $[Ni(CN)_4]^{2-}$ is square planar and diamagnetic complex with $dsp^2$ hybridization for $Ni$ but $[Ni(CO)_4]$ is tetrahedral,diamagnetic and with $sp^3$ hybridization for $Ni$.
Statement $II$: $[NiCl_4]^{2-}$ and $[Ni(CO)_4]$ both have same $d$-electron configuration,have same geometry and are paramagnetic.
In light of the above statements,choose the correct answer from the options given below:

Write the limitations of Valence Bond Theory $(VBT)$.

The hexafluoroferrate$(III)$ ion is an outer orbital complex. The number of unpaired electrons in it is.....

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