Dipole: A dipole is said to exist when two charges of equal magnitude but opposite signs are separated by a small distance.

The overall dipole in a molecule depends on:

The electronegativity of the elements in the molecule
- If there is a large electronegativity difference between the elements in the molecule, this will increase the magnitude of the dipole
The relative angles of the bonds
- If the molecule is symmetrical in all directions, the individual dipoles will cancel each other out and the molecule will be non-polar.
- If the molecule is not symmetrical in all directions, then the dipoles will reinforce each other, the molecule will possess an overall dipole and is said to be polar.