Write a note on: Enantiomers.

Optical isomerism occurs when compounds have the same molecular formula and sequence of bonded atoms but differ in the 3D orientation of their atoms, specifically being non-superimposable mirror images of each other. These isomers, called enantiomers, contain at least one chiral center (usually a carbon atom bonded to four different groups). Optical isomers rotate plane-polarized light in opposite directions.