Pauling's electronegativity scale is based upon experimental values of

${\mathrm{X}}_{\mathrm{A}}-{\mathrm{X}}_{\mathrm{B}}=0.102\mathrm{\hspace{0.17em}}{\left[{\mathrm{E}}_{\mathrm{A}-\mathrm{B}}-\frac{1}{2}\left({\mathrm{E}}_{\mathrm{A}-\mathrm{A}}\mathrm{\hspace{0.17em}\hspace{0.17em}}\times \mathrm{\hspace{0.17em}\hspace{0.17em}}{\mathrm{E}}_{\mathrm{B}-\mathrm{B}}\right)\right]}^{1/2}$

Where ${\mathrm{X}}_{\mathrm{A}}\mathrm{and}{\mathrm{X}}_{\mathrm{B}}$ are EN of atom A and B, ${\mathrm{E}}_{\mathrm{A}-\mathrm{A}},{\mathrm{E}}_{\mathrm{B}-\mathrm{B}}\mathrm{and}{\mathrm{E}}_{\mathrm{A}-\mathrm{B}}$ are bond energies of molecules of ${\mathrm{A}}_2,{\mathrm{B}}_2\mathrm{and}\mathrm{AB}.$