A dipole moment is a measure of the separation of positive and negative charges within a molecule. It arises when there is an asymmetrical distribution of electrons, leading to a partial positive charge on one end of the molecule and a partial negative charge on the other end. This creates a permanent electric dipole, with a positive and negative pole separated by a certain distance.

Mathematically, the dipole moment (μ) is defined as the product of the magnitude of the charge (q) and the distance of separation (d) between the charges:

μ=q⋅d

The SI unit of dipole moment is the coulomb-meter (C·m), although it is commonly expressed in debye (D) in chemistry, where 1 debye is approximately 3.336×10−303.336×10−30 C·m.

Dipole moments are important in understanding the behavior of molecules in various contexts, such as in chemistry, where they influence molecular polarity, intermolecular interactions, and properties like solubility and reactivity.