How many unpaired electrons are present in the cobalt ion in the $+3$ oxidation state prior to hybridization in the $[CoF_6]^{3-}$ complex ion?

$NiCl_2\{P(C_2H_5)_2(C_6H_5)\}_2$ exhibits temperature-dependent magnetic behaviour (paramagnetic/diamagnetic). The coordination geometries of $Ni^{2+}$ in the paramagnetic and diamagnetic states are respectively

What type of hybridisation is present in square planar geometry of complex $[Ni(CN)_4]^{2-}$?

The geometry of $[Pt(NH_3)_4]Cl_2$ is:

The number of isoelectronic species among $Sc^{3+}$, $Cr^{2+}$, $Mn^{3+}$, $Co^{3+}$, and $Fe^{3+}$ is $n$. If $n$ moles of $AgCl$ are formed during the reaction of the complex with the formula $CoCl_{3}(en)_{2}NH_{3}$ with excess $AgNO_{3}$, then the number of electrons present in the $t_{2g}$ orbital of the complex is . . . . . . .

Identify the complex having the highest number of unpaired electrons from the following: