Electronegativity: A continuing enigma

There continues to be confusion concerning the concept of electronegativity. Pauling's original approach, focusing upon an atom in a molecule, continues to be widely invoked. There has also been a more recent tendency to view electronegativity as the negative of the chemical potential and to extend it to molecules. However, this leads to results that are incompatible with chemical experience. A more effective approach, which gives results in overall agreement with Pauling's values, is to relate electronegativity to the average valence electron ionization energies of atoms.