Question

What is the difference between polar and non-polar compounds?

Answer 1

POLAR:
In molecules in which the electro-negativity values (the power of an atom to pull the shared pair of electrons towards itself) is very different between the bonded atoms(usually greater than 1.7), the molecule with higher electronegativity attracts the shared pair toward itself due to which a slight -ve charge appears on it and because of relative deficiency of electrons in the other atom(because of distance from the electron pair), the other atom shows a slight +ve charge.
That is why these molecules are called polar because two poles (slight -ve on one side and slight +ve on the other are created).

NON-POLAR:
In these molecules, the electro-negativity difference among the atoms is zero or insignificant. Thus there will be no appearance of charges and no poles.

Bond Polarity Electronegativity Diff.