Electroaffinity or electronegativity X LL is approximately proportional to the average ionization energy B , the total ionization energy U divided by the number of atomic valence shell electrons N , due to its vecy small electron affinity E . Furthermore, electroaffinity of the atomic valence and/or hybridization orbital can be also obtained from their individual capability of attracting valence electrons of an atomic valence and/or hybridization orbital by the ionization energies of valence electron in ground stated free atom and its various orbitals.