DIPOLE

"A pair of equal and opposite electrical charges separated by a small distance. A dipole will align itself, if possible, in the presence of other electrical charges according to the attraction of opposite and repulsion of like charges. Externally electrically neutral chemical molecules can have a dipole inside. E.g., water is a triangular molecule with the oxygen at one corner and the two hydrogens at the other two corners. The internal charge distribution is such that the hydrogen side has a slight excess of positive charge and the oxygen end is correspondingly negative. A dipole is characterized by its ""dipole moment,"" the product of the charge and the separation distance (coulomb times centimeter). "