Dipole Moment
The vector measure of the separation of positive and negative charge in a bond or molecule.
Formula / equation
μ = q × d
Unit
D
In depth
Measured in debye, the dipole moment is the vector sum of all bond dipoles and lone-pair contributions, so a molecule with polar bonds can still be non-polar if the geometry is symmetric. Dipole moments determine solubility patterns, boiling points and how a substance responds to an electric field.
Examples in the real world
Water 1.85 D and NH₃ 1.47 D are polar; CO₂ and CCl₄ measure 0 D because their bond dipoles cancel.