Question

what are various element of symmetry?give one example ilustrating the presence of elements inthem

Answer 1

The symmetry of a molecule is determined by the existence of symmetry operations performed with respect to symmetry elements. A symmetry element is a line, a plane or a point in or through an object, about which a rotation or reflection leaves the object in an orientation indistinguishable from the original.

Examples cis-1,2-Dichloroethene 
trans-1,2-Dichloroethene 
cis-1,2-Dimethylcyclopropane