Polar Covalent Bonds

Electronegativity

is defined as the attraction of an atom for a bonding pair of electrons.

What element has the highest electronegativity

Fluorine (4.0 on Pauling scale)

Polar covalent bonds

occur between atoms that have a difference in electronegativity of between 0.5 and 1.7 units. 

Since the bonding electrons are not equally shared between the atoms

The unequal sharing of electrons in a bond creates a bond dipole.

A bond dipole will result in

one atom in the bond having a partial positive charge and the other having a partial negative charge.

How are these partial negative and positive charges shown

shown by the δ+ and δ- signs

Ionic bonds (electronegativity)

More than 1.8

Polar covalent bonds (electronegativity)

0 to 1.8

Covalent bonds (electronegativity)

less than 1.8