The power of an atom in a molecule to attract electrons to itself.

1. A numerical expression of the relative negativity of various substances, based on calculations that use bond energies and which assign a value of four to fluorine, the most electronegative element.

A system proposed by Linus Carl Pauling (1901–1994).

2. A numerical scale of electronegativities that are based on bond-energy calculations for different elements joined by covalent bonds.