Sachin, an object that is non superimposable on its mirror image is said to be chiral object and which is superimposable on its mirror image is achiral. Chiral compounds are unsymmetric as the carbon which is known as the chiral carbon is attacked to 4 different atoms or group of atoms. The chiral carbons are also known as Stereogenic centres and the chiral molecules do not have a plane of symmetry due to unsymmetry in their structure. The molecules which are chiral in nature, are optically active and optically active molecules should always be chiral a stereogenic centre( if the stereogenic centres are more than 1, then the molecule msy be chiral or achiral) . However, there are exceptions to this as observed in case of amines, where Nitrogen is a stereogenic centre but its optical activity is abolished due to the phenomenon of Pyramidal inversion.