Which of the following has a square planar shape?

Give the correct sequence of initials $T$ or $F$ for the following statements. Use $T$ if the statement is true and $F$ if it is false.
$(I) \ Co(III)$ is stabilized in the presence of weak field ligands,while $Co(II)$ is stabilized in the presence of strong field ligands.
$(II)$ Four-coordinated complexes of $Pd(II)$ and $Pt(II)$ are diamagnetic and square planar.
$(III) \ [Ni(CN)_4]^{4-}$ ion and $[Ni(CO)_4]$ are diamagnetic tetrahedral and square planar respectively.
$(IV) \ Ni^{2+}$ ion does not form inner orbital octahedral complexes.

Which of the following pairs of compounds is planar?

$[FeF_6]^{3-}$ has ........ hybridisation and ....... geometry. Select the best option to fill the blank space respectively:

Which one of the following has a square planar geometry?

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