Polarity

In physics, polarity describes an attribute that can usually have two values:

• An electric charge has a polarity of either positive or negative.
• A voltage has a polarity, in that it could be positive or negative (with respect to some other voltage, such as the one at the other end of a battery or electric circuit).
• A magnet has a polarity, in that one end is the "north" and the other is the "south".
• The spin of an entity in quantum mechanics has a polarity - positive or negative.
• Polarized light has waves which all line up in the same direction.

Chemical polarity is a feature of chemical bonds, where two different atoms in the same molecule have different electronegativity. As a result, the electrons in the bond are not shared equally by the two atoms. This causes an asymmetrical (polar) electric field. Molecular covalent bonds can be described as polar or nonpolar. Entire molecules can also be described as polar.