Square-planar geometry is shown by

The geometries of some complex ions are given below. Select the correct answer.
$(1) [Ag(NH_3)_2]^+ - \text{Linear}$
$(2) [MnCl_4]^{2-} - \text{Tetrahedral}$
$(3) [Cu(NH_3)_4]^{2+} - \text{Square planar}$
$(4) [Ni(CN)_4]^{2-} - \text{Square planar}$

Among the following,the species having square planar geometry for the central atom are:
$(i)$ $XeF_4$
$(ii)$ $SF_4$
$(iii)$ $[NiCl_4]^{2-}$
$(iv)$ $[PtCl_4]^{2-}$

The number of unpaired electrons in $[NiCl_{4}]^{2-}$, $Ni(CO)_{4}$ and $[Cu(NH_{3})_{4}]^{2+}$ respectively are

Consider the following test for a group-$IV$ cation.
$M^{2+} + H_2S \rightarrow A$ (Black precipitate) $+$ byproduct
$A + \text{aqua regia} \rightarrow B + NOCl + S + H_2O$
$B + KNO_2 + CH_3COOH \rightarrow C + \text{byproduct}$
The spin only magnetic moment value of the metal complex $C$ is $BM$. (Nearest integer)

$d^{2}sp^{3}$ hybridisation of the atomic orbitals gives