If crystal field stablization energy of ${\left[{\mathrm{ML}}_6\right]}^{+\mathrm{n}}$ is $-0.8 {∆}_{\mathrm{o}}$.

Find minimum number of electrons in ${\mathrm{t}}_{2_{\mathrm{g}}}$ orbitals of metal ion?

Find number of $\mathrm{Co}-\mathrm{N}$ linkage in,

Pentaamminecobalt$\left(\mathrm{III}\right)-\mu -$ amidodiamminetriaquacobalt$\left(\mathrm{III}\right)$ chloride.

Find the number of species from the following which has magnetic moment value of $1.73$ B.M.

${\mathrm{Fe}}^{2+},{\mathrm{Cu}}^{2+},{\mathrm{Ni}}^{2+},{\mathrm{NO}}_2,{\mathrm{NO}}_2^{-},{\mathrm{Sc}}^{2+}$