An Etymological Dictionary of Astronomy and Astrophysics

A molecule in which the centers of positive and negative charge distribution do not converge and therefore has a mostly positive charge on one side and a mostly negative charge on the other. Different atoms around a central atom will always be polar molecules. Some polar molecules are H₂O, HF, COS, and CH₃Cl. Polar molecules are characterized by a → dipole moment.

See also: → polar; → molecule.