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The INTERNET Database of Periodic Tables

There are thousands of periodic tables in web space, but this is the only comprehensive database of periodic tables & periodic system formulations. If you know of an interesting periodic table that is missing, please contact the database curator: Mark R. Leach Ph.D.

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Vernon's Constellation of Electronegativity

René Vernon has created a "Constellation of Electronegativity" by plotting Electronegativity against Elemental Orbital Radii (rorb)

Observations on the EN plot:

    1. The results are similar to the orbital radii x EA plot, although not quite as clear, including being more crowded
    2. Very good correspondence with natural categories
    3. Largely linear trends seen along groups 1-2, 17 and 15-18 (Ne-Rn)
    4. First row anomaly seen for He (or maybe not since it lines up with the rest of group 2)
    5. For group 13, the whole group is anomalous
    6. For group 14 , the whole group is anomalous no doubt due to the scandide contraction impacting Ge and the double whammy of the lanthanide and 5d contraction impacting Pb
    7. F and O are the most corrosive of the corrosive nonmetals
    8. The rest of the corrosive nonmetals (Cl, Br and I) are nicely aligned with F
    9. The intermediate nonmetals (IM) occupy a trapezium
    10. Iodine almost falls into the IM trapezium
    11. The metalloids occupy a diamond, along with Hg; Po is just inside; At a little outside
    12. Rn is metallic enough to show cationic behaviour and falls into the metalloid diamond
    13. Pd is located among the nonmetals
    14. The proximity of H to Pd is again (coincidentally?) curious given the latter's capacity to adsorb the former
    15. The post-transition metals occupy a narrow strip overlapping the base of the refractory metal parallelogram
    16. Curiously, Zn, Cd, and Hg (a bit stand-off-ish) are collocated with Be, and relatively distant from the PTM and the TM proper
    17. The ostensibly noble metals occupy an oval; curiously, W is found here; Ag is anomalous given its greater reactivity; Cu, as a coinage metal, is a little further away
    18. Au and Pt are nearest to the halogen line
    19. The ferromagnetic metals (Fe-Co-Ni) are colocated
    20. The refractory metals, Nb, Ta, Mo, W and Re are in a parallelogram, along with Cr and V; Tc is included here too
    21. Indium is the central element of the periodic table in terms of mean orbital radius and EN; Tc is next as per the EA chart
    22. The reversal of He compared to the rest of the NG reflects #24
    23. All of the Ln and An fall into an oval of basicity, bar Lr
    24. The reversal of the positions of Fr and Cs is consistent with Cs being the most electronegative metal
    25. A similar, weaker pattern is seen with Ba and Ra. 

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What is the Periodic Table Showing? Periodicity

© Mark R. Leach Ph.D. 1999 –

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