(A-q,r,t), (B-q,r,t),(C-p,s),(D-r,s).
(A) `d^(6)` - configurration, `Co^(3+) rarrd^(2)sp^(3)` diamagnetic. En multidentate ligand - chelation possible.
(B) `d^(6)` - configuration, `Co^(3+)` and diamagnetic `rarrd^(2)sp^(3)` Stabillsation through helation -ox multidentate ligand.
( C) `d^(7)` - configuration, `Co^(2+)` and paramagnetic with three unpaired electrons - `sp^(3)d^(2)` (`H_(2)O` weak field ligand).
(D) `d^(7)` - configuration `Co^(2+)` and paramagnetic, one electron jumps to 5s - orbital, `d^(2)sp^(3)`
