If the magnetic moment of $[Ag(CN)_2]^{-1}$ is zero,then the number of unpaired electrons will be

In an octahedral complex of the type $Ma_3b_3$,where $M$ is a metal ion and $a$ and $b$ are two different types of ligands,what are the two possible geometric isomers?

For a transition metal with a $d^7$ configuration,the magnetic susceptibility (magnetic moment) is ........ $B.M.$

Consider the following low-spin complexes: $K_3[Co(NO_2)_6]$,$K_4[Fe(CN)_6]$,$K_3[Fe(CN)_6]$,$Cu_2[Fe(CN)_6]$,and $Zn_2[Fe(CN)_6]$. The sum of the spin-only magnetic moment values of complexes having yellow colour is $.......... B.M.$ (answer is nearest integer).

Which of the following complexes exhibits both geometric and optical isomerism?

Of the following configurations,the optical isomers are