The difference in the number of unpaired electrons of a metal ion in its high spin and low-spin octahedral complexes is two. The metal ion is :

A reaction of cobalt (III) chloride and ethylenediamine in a 1 : 2 mole ratio generates two isomeric products A (violet coloured) and B (green coloured). A can show optical activity, but B is optically inactive. What type of isomers does A and B represcent?

The total number of isomers for a square planar complex
[M(F)(Cl)(SCN)(NO₂)] is

Homoleptic octahedral complexes of a metal ion 'M³⁺' with three monodenate ligands L₁, L₂ and L₃ adsorb wavelenths in the region of green, blue and red respectively. The increasing order of the ligands strength is :