What are polar and non-polar molecules ? Give their examples.

Explanation

The molecules in which the centres of positive charges and of negative charges lie at the same place, therefore, their dipole moment is zero are called non-polar molecule. `CO_(2)` and `CH_4` are examples.
They develop a dipole moment when an electric field is applied.
But in some molecules, the centres of negative charges and of positive charges do not coincide. Therefore they have a permanent electric dipole moment even in the absence of an electric field. Such molecules are called polar molecules.`H_(2)O, HCl` are examples.