Explain Polar Covalent bond with a suitable example.

Explanation

When a covalent bond is formed between two similar atoms, for example in `H_(2), O_(2)Cl_(2), N_(2) " or " F_(2)` the shared pair of electrons is equally attracted by the two atoms. So the shared electron pair is situated exactly between the two identical nuclei. The bond so formed is non-polar covalent bond.
If a bond is formed between atoms of different elements to form heteronuclear molecule like HF the shared electron pair between the two atoms gets displaced more towards fluorine since the electronegativity of fluorine is more than that of hydrogen. As a result partial negative charge develops on fluorine atom while an equal amount of partial positive charge develops on hydrogen atom.
`delta_(+) " " delta-`

The resultant covalent bond becomes polar covalent bond. The direction of the displacement of electron is represented with an arrow mark on the bond.