Summary:
- A polar molecule is a molecule in which one end of the molecule is slightly positive, while the other end is slightly negative.
- The two electrically charged regions on either end of a molecule are called poles, similar to a magnet having a north and a south pole.
- For molecules with more than two atoms, the molecular geometry must also be taken into account when determining if a molecule is polar or nonpolar.
- A tetrahedral molecule such as CH4 is not polar, but if one of the peripheral H atoms is replaced with another atom that has a different electronegativity, it is.