In Cr 2 O 72– , the valence shell electron configuration of Cr(VI) is 3d 0 . Thus Cr(VI) is diamagnetic but coloured due to the charge transfer spectrum.

In (NH 4 ) 2 [TiCl 6 ], the valence shell electron configuration of Ti(IV) is 3d 0 . Thus Ti(IV) is diamagnetic and colourless.

In VOSO 4 , the valence shell electron configuration of V(IV) is 3d 1 . Thus V(IV) is paramagnetic and blue coloured due to d-d transition.

In K 3 [Cu(CN) 4 ], the valence shell electron configuration of Cu(I) is 3d 10 . Thus Cu(I) is diamagnetic and colourless.