Which one of the following complexes will have $\Delta_0 = 0$ and $\mu = 5.96 \ B.M.?$

Absorbed colour of the solutions of the following complexes $[M(NH_3)_6]^{2+}$,$[M(H_2O)_6]^{2+}$ and $[MCl_4]^{2-}$ are respectively (having the same metal ion):

Which of the following complex ions absorbs the light of minimum wavelength?

The $3d$ metal ions form coloured compounds because the energy corresponding to the following lies in the visible range of the electromagnetic spectrum:

Arrange the following ligands in the order of increasing field strength:
$H_2O$ $(I)$,$CO$ $(II)$,$NH_3$ $(III)$,$I^{-}$ $(IV)$,$F^{-}$ $(V)$

Arrange the following Cobalt complexes in the order of increasing Crystal Field Stabilization Energy $(CFSE)$ value.
Complexes: $[CoF_{6}]^{3-}, [Co(H_{2}O)_{6}]^{2+}, [Co(NH_{3})_{6}]^{3+}$ and $[Co(en)_{3}]^{3+}$
$A: [CoF_{6}]^{3-}, B: [Co(H_{2}O)_{6}]^{2+}, C: [Co(NH_{3})_{6}]^{3+}, D: [Co(en)_{3}]^{3+}$
Choose the correct option: