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 structureO H HThe 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