Dipole moment (μ) is a quantitative measure of the polarity of a bond or molecule, equal to the magnitude of the separated charge multiplied by the distance between the charges. A larger dipole moment indicates a more polar species. The molecular dipole moment is the vector sum of the individual bond dipoles, so a molecule with polar bonds can still be nonpolar if they cancel.

偶极矩(μ)是键或分子极性的定量量度,等于所分离电荷的大小乘以电荷间的距离。偶极矩越大,表明物种极性越强。分子偶极矩是各键偶极的矢量和,因此即使含有极性键,若它们相互抵消,分子仍可为非极性。