Covalent Bonding

A covalent bond occurs when electron pairs are shared by two different atoms. Covalent bonds can be polar or non polar. Polar covalent bonds occur when one end of the molecule is slightly negative and the other end is slightly positive. This happens when atoms share a pair of electrons unequally. When the electrons are shared equally the bond is non polar and both sides are equal in charge.

Electronegativity measures the tendency of an atom to attract electron pairs. Electronegativity (EN) values range from .7-4. A higher value implies a higher attraction of electron pairs.

Polar covalent bonds occur when ΔEN≠0.

Non polar covalent bonds when Δ EN=0.

The periodic table below shows the electronegativity values of different elements.