The hybridisation and geometry of $[Ni(CN)_4]^{2-}$ are:

What is the shape of $Fe(CO)_5$?

Complexes $(ML_5)$ of metals $Ni$ and $Fe$ have ideal square pyramidal and trigonal bipyramidal geometries,respectively. The sum of the $90^{\circ}$,$120^{\circ}$ and $180^{\circ}$ $L-M-L$ angles in the two complexes is

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 statements are correct?
$i$. $[Mn(CN)_6]^{3-}, [MnCl_6]^{3-}$ both are paramagnetic
$ii$. Both $[NiCl_4]^{2-}, [Ni(CO)_4]$ are tetrahedral and diamagnetic
$iii$. $[Co(NH_3)_6]^{3+}$ is an inner orbital complex,but $[Ni(NH_3)_6]^{2+}$ is an outer orbital complex

Octahedral complexes of copper $(II)$ undergo structural distortion (Jahn-Teller). Which one of the given copper $(II)$ complexes will show the maximum structural distortion?
($en = \text{ethylenediamine}$; $H_2N-CH_2-CH_2-NH_2$)