Linus Pauling proposed the concept of electronegativity based on the bond energies of atoms in molecules. He observed that the actual bond energy of a heteronuclear bond (between different atoms) is often higher than the average of the bond energies of homonuclear bonds. This additional stabilization was attributed to the difference in electronegativity between the atoms. Therefore, Pauling’s electronegativity values are based on bond energy.
The correct option is (D): bond energy