Polar molecule

In chemistry, a polar molecule is one that has concentrations of positive or negative electric charge. A commonly-used example of a polar compound is water (H₂O). It has the structure

   O
 H   H

The electrons of the hydrogen atoms are strongly attracted to the oxygen atom, and are actually closer to its nucleus than to those of the hydrogens. Thus, the molecule has a strong negative charge in the middle, and a positive charge at the ends.

Polar compounds are soluble only in other polar compounds.

See also: nonpolar, hydrophilic