Dipole moment

Building on the qualitative picture of polar bonds already developed in section 5.6.5, dipole moment is formally DEFINED as the product of the magnitude of the separated charge (Q) and the distance of separation (r) between the centres of positive and negative charge within a molecule: $\mu = Q\times r$. Its everyday practical unit is the Debye (D), related to the coherent SI unit of charge-times-distance by $1\ \text{D} = 3.33564\times10^{-30}\ \text{C m}$ (C = coulomb, the SI unit of electric charge; m = metre, the SI unit of distance) — a Debye-scale value is far more convenient to write and compare than the correspondi …