To understand why, hold a glove and a mitten in front of a mirror. There is no difference between the mitten shown in the figure below and its mirror image. There is a difference, however, between the glove and its mirror image. The mirror image of the glove that fits the left hand looks like the glove that fits the right hand, and vice versa. Each member of a pair of gloves is the mirror image of the other the way the right and left hands are mirror images of each other.
Gloves therefore have the same property as the hands on which they are placed.
By definition, any object that has a mirror image that is different from itself is chiral. These isomers have almost identical physical and chemical properties. They have the same melting point, boiling point, density, and color, for example. They differ only in the way they interact with plane-polarized light. Active Compounds Light consists of electric and magnetic fields that oscillate in all directions perpendicular to the path of the light ray.