Polarization
Definition and meaning of Polarization in chemistry.
Polarization is the separation or redistribution of electron charge density in a molecule, atom, or bond, creating dipole moments and partial charges.
In more detail
Polarization occurs when atoms in a covalent bond differ in electronegativity, causing electron density to shift toward the more electronegative atom and creating a dipole moment. This intrinsic polarization is fundamental to understanding why some molecules are polar, and even nonpolar molecules can be temporarily polarized when exposed to an external electric field. Polarization explains many chemical phenomena including solubility patterns, intermolecular forces like hydrogen bonding, and molecular reactivity.
Key facts
| Field | Physical Chemistry |
|---|---|
| Cause | Electronegativity difference between atoms |
| Measured by | Dipole moment |
| Examples | HCl, H2O |
In hydrogen chloride (HCl), chlorine is more electronegative than hydrogen, so electron density shifts toward the chlorine atom, creating a permanent dipole with the chlorine carrying a partial negative charge and hydrogen carrying a partial positive charge.
Frequently asked questions
What is the difference between a polar molecule and polarization?
Polarization is the process of charge separation that occurs in molecules. A polar molecule is one that has permanent polarization due to asymmetric charge distribution.
Can nonpolar molecules be polarized?
Yes, all molecules can be induced to form temporary dipoles when exposed to an external electric field, a phenomenon called induced polarization.