Compounds having either C=C or C=N exhibit geometrical isomerism but the other main condition for exhibiting geometrical isomerism is the presence of two different groups on double bonded carbon atoms.
Since in ketoxime, (CH3)2C=NOH, two same (−CH3) groups are present on double bonded carbon atom, its other form is not possible and it does not exhibit geometrical isomerism.
Compounds with N=N also have two geometrical forms as
