The number of geometrical isomers found in the metal complexes $[PtCl_2(NH_3)_2]$,$[Ni(CO)_4]$,$[Ru(H_2O)_3Cl_3]$ and $[CoCl_2(NH_3)_4]^+$ respectively,are :

The calculated spin-only magnetic moments of $K_3[Fe(OH)_6]$ and $K_4[Fe(OH)_6]$ respectively are $:$

$A$ complex of a certain metal has a magnetic moment of $4.91 \ BM$,whereas another complex of the same metal with the same oxidation state has zero magnetic moment. The metal ion could be:

Consider the following metal complexes:
$1. [Co(NH_3)_6]^{3+}$
$2. [CoCl(NH_3)_5]^{2+}$
$3. [Co(CN)_6]^{3-}$
$4. [Co(NH_3)_5(H_2O)]^{3+}$
The spin-only magnetic moment value of the complex that absorbs light with the shortest wavelength is $B.M.$ (Nearest integer).

The magnetic moment of the complex $[Cr(CN)_6]^{3-}$ is ..... (in $BM$)

Which of the following complexes exhibits the highest paramagnetic behaviour? (where $gly = \text{glycine}$,$en = \text{ethylenediamine}$,and $bpy = \text{bipyridyl}$ moieties. At. nos. $Ti = 22, V = 23, Fe = 26, Co = 27$)