Asymmetric (or chiral) carbon atom is that carbon atom, which is bonded to four different atoms or groups, e.g. $ \alpha \text{-} $ chloropro-piordc acid has a chiral carbon atom. $ {{H}_{3}}C--\underset{Cl}{\overset{H}{\mathop{\underset{|}{\overset{|}{\mathop{{{C}^{*}}}}}\,}}}\,--COOH $