Explain polar and non polar covalent bonds with examples.

Hi,

A covalent bond formed between two different atoms, with different electronegativities is known as polar covalent bond.

For example when a Covalent bond is formed between H and Cl, it is polar in nature because Cl is more  electronegative than H atom. Therefore, electron cloud is shifted towards Cl atom. As a result, a partial negative charge appears on Cl atom and, an equal positive charge on H atom.  

H^δ+----Cl^δ-

A covalent bond formed between two like atoms, is known as Non-polar bond. Since difference of electronegativity is zero, therefore, both atoms attract electron pair equally and no charge appears on any atom, and the whole molecule becomes neutral.

For e.g. H------H

Hope it helps.

Enjoy learning!!