WebElements Periodic Table of the Elements | Periodicity | Electronegativity (Allen) | periodicity

	Electronegativity (Allen) L.C. Allen suggests that electronegativity is the average one-electron energy of the valence shell electrons in the ground state free atoms. This means that values of the Allen electronegativity can be calculated from spectroscopic data. The values obtained correlate well with Pauling electronegativity and with Allred-Rochow electronegativity. The Allen electronegativity is given the symbol Χ_spec. Units Pauling scale Notes The Allen electronegativity is given the symbol Χ_spec. For the s- and p-block elements, then: Χ_spec = (mε_s + nε_p)/(m + n) where m = number of s-electrons n = number of p-electrons ε_p = p ionization energy ε_s = s ionization energy Literature sources L.C. Allen, J. Am. Chem. Soc., 1989, 111, 9003. J.E. Huheey, E.A. Keiter, and R.L. Keiter in Inorganic Chemistry : Principles of Structure and Reactivity, 4th edition, HarperCollins, New York, USA, 1993. WebElements Shop WebElements now has an online shop at which you can buy periodic table posters, mugs, T-shirts, games, molecular models, and more.
Periodicity Cityscape Cylinders Line graph Bar chart Group 1 Group 2 Group 13 Group 14 Group 15 Group 16 Group 17 Group 18 Period 2 Period 3 Period 4sp Period 4 Period 5sp Period 5spd s- and p-Block		Search WebElements Search Chemistry Web Custom Search Essential data Essential data: name, symbol, atomic number, and atomic weight; block, period, group number, and group name in periodic table; description; standard state; registry number; and isolation History: meaning of name; discovery; and history of the element Find a property The elements round us Uses Geology: Abundance of elements in the universe; the sun; meteorites; Earth's crust; oceans; and streams Biology: abundance in humans; biological role; and health hazards Compounds Compounds: halides, oxides, sulfides, hydrides, and complexes; lattice energies; and reduction potentials Electronegativities: Pauling; Sanderson; Allred-Rochow; Mulliken-Jaffe; and Allen Bond enthalpies of diatomic species Lattice energies: oxides and halides Element properties Physics properties: boiling point; melting point; density; and molar volume; thermal conductivity; and electrical resistivity; bulk modulus; critical temperature; superconductivity temperature; hardness (mineralogical, Brinell, and Vickers); linear expansion coefficient; Poisson's ratio; reflectivity; refractive index; rigidity modulus; Young's modulus; and velocity of sound Images Allotropes Reactions of : reactions with air; water; halogens; acids; and bases Crystal structure Thermochemistry: enthalpies of atomisation, fusion, and vaporisation, thermodynamic properties Atom properties Electronic properties: electronic configuration; term symbol; electron affinity; ionisation energies; and atomic spectra Atom sizes: atomic radii; Shannon and Pauling Ionic radii; covalent radius; metallic radius; element bond length; and Van der Waals radius Electron shell properties: effective nuclear charge; electron binding energies; and valence orbital radii maxima Nuclear properties Isotopes: isotope abundances; radioactive isotopes; isotope masses; nuclear spins; and nuclear magnetic moments NMR properties: frequencies; NMR isotopes; magnetogyric ratios; quadrupole moments; receptivities; and relative sensitivities Books Chemistry Books (CA) Chemiebücher (DE) Livres de chimie (FR) Medical Bookshop (UK) Medical Bookstore (USA) Physics Bookshop (UK) Biology Bookshop (UK) Law, Business, and Finance Bookshop (UK) Scientific book store (USA) Scientific book store (UK)