polarizabilitet

Polarizabilitet is a measure of how easily the electron cloud of an atom or molecule can be distorted by an external electric field. This distortion can be induced by a nearby charged particle or by an electromagnetic wave. When an electric field is applied, the positive nuclei and negative electrons within the atom or molecule experience opposing forces, leading to a separation of charge. This induced separation of charge creates an electric dipole moment.

The magnitude of this induced dipole moment is directly proportional to the strength of the applied electric field, and the proportionality constant is known as the polarizabilitet. A higher polarizabilitet means that the electron cloud is more easily distorted, resulting in a larger induced dipole moment for a given electric field. This property is crucial in understanding various physical phenomena, including the dielectric properties of materials, intermolecular forces, and the interaction of light with matter.

Polarizabilitet is an intrinsic property of a substance and depends on its electronic structure. Atoms and molecules with more diffuse and loosely bound electrons tend to have higher polarizabilitet. For example, larger atoms with electrons in higher energy shells are generally more polarizable than smaller atoms. Similarly, molecules with delocalized pi electron systems, such as conjugated organic compounds, exhibit significant polarizabilitet. It is often expressed in units of volume, such as cubic angstroms (ų) or cubic meters (m³), or in SI units as the polarizabilitet of a point charge that creates the same dipole moment when placed in a uniform electric field.