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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.

Use the drop menus below to search & select from the more than 1100 Period Tables in the database:

Text search:       

Periodic Table database entries referencing the term electronegativity, by date:

1836   Berzelius' Electronegativity Table
1870   Baker's Electronegativity Table
1886   Discovery of Fluorine
1893   Rang's Periodic Arrangement of The Elements
1895   Thomsen's Systematic Arrangement of the Chemical Elements
1960   Pauling's Complete Electronegativity Scale
1971   Satz's Reciprocal System Periodic Table
1987   Elsevier's Periodic Table of the Elements
1993   WebElements: The Periodic Table on The Web
2003   Electronegativity Periodic Table
2003   Electronegativity Periodic Table
2005   Extraction from Ore to Pure Element
2006   Where Should Hydrogen Go?
2006   Reaction Chemists' Periodic Table
2013   Electronegativity Chart (Leach)
2013   Top 10 Periodic Tables
2013   Averaged Ionisation Potential Periodic Table
2018   Acid-Base Behavior of 100 Element Oxides
2018   First Ionisation Energy to the Standard Form Periodic Table
2020   Correlation of Electron Affinity (F) with Elemental Orbital Radii (rorb)
2020   Vernon's Constellation of Electronegativity


Berzelius' Electronegativity Table

Berzelius' electronegativity table of 1836.

The most electronegative element (oxygen or Sauerstoff) is listed at the top left and the least electronegative (potassium or Kalium) lower right. The line between hydrogen (Wasserstoff) and gold seperates the predomently electronegative elements from the electropositive elements. Page 17 and ref. 32 from Bill Jensen's Electronegativity from Avogadro to Pauling Part I: Origins of the Electronegativity Concept, J. Chem. Educ., 73, 11-20 (1996):

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Baker's Electronegativity Table

Baker's electronegativity table of 1870 differs from Berzelius' listing of 1836 only by the addition of the newly discovered elements. Page 280 and ref. 5 from Bill Jensen's: Electronegativity from Avogadro to Pauling Part II: Late Nineteenth- and Early Twentieth-Century Developments, J. Chem. Educ., 80, 279-287 (2003):

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Discovery of Fluorine


Fluorine, atomic number 9, has a mass of 18.998 au.

Fluorine exists as a pale yellow diatomic molecular gas, F2. It is the most electronegative and reactive of all elements: it which reacts with practically all organic and inorganic substances.

Fluorine was first observed or predicted in 1810 by A.-M. Ampére and first isolated in 1886 by H. Moissan.

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Rang's Periodic Arrangement of The Elements

P.J.F. Rang's The Periodic Arrangement of the Elements, Chemical News, vol. 67, p. 178 (1893)

Observing that that Rang's table has four 'groups': A, B, C & D, René Vernon writes:

    1. Group A contains the strongest positive elements; group D the strongest negative elements. At such an early date, it's odd to see groups 1 to 3 categorised together.
    2. Group B are the elements with high melting points; "they are all remarkable for their molecular combinations" (presuamably, a reference to multiple oxidation states). At one side of group B are the "anhydro-combinations", probably referring to the simple chemistry of Ti, Zr, [Hf] Nb and Ta being dominated by insoluble oxides. At the other side are the "amin, carbonyl, and cyanogen combination", probably a reference to the group VIII carbonyls, as metal carbonyls had only just been discovered. Ni is shown after Fe, rather than Co.
    3. Group C includes the "heavy metals that have low melting points"; an early reference to frontier or post-transition metals, as a category.
    4. Rang says: ...if groups A and D be split up vertically in respectively three and two parts, the table presents seven vertical groups, and horizontally seven more or less complete series. Each group in each of the series 2 and 3 are represent by one element... The octave appears both horizontally and vertically in the table.
    5. Rang's reference to Di as representing all the triads between Ba and Ta kind of works since Hf would go under Zr, and that would leave 15 Ln or five sets of three. Thus, something like this:

      Gd occupies the central position among the Ln. This arrangement won't fit however unless Rang envisaged all 15 Ln occupying the position under Y.
    6. The location of H over | Ga | In | Tl, appears strange... but the electronegativity of H (2.2) is closer to B (2.04) than it is to C (2.55).

From Quam & Quam's 1934 review paper.pdf

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Thomsen's Systematic Arrangement of the Chemical Elements

In 1895 the Danish thermochemist Hans Peter Jørgen Julius Thomsen proposed (Thomsen, J., 1895. Z. Anorg. Chem. 9, 190 & Chemical News, 72, 89–91, p. 90) a pyramidal/ladder representation.

Notice how this formulation identifies the electropositive & electronegative elements with respect to the periodic table, thirty years before Linus Pauling.

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Pauling's Complete Electronegativity Scale

From The Nature of The Chemical Bond, 3rd Ed, pp 93, Pauling gives a periodic table showing the electronegativity of the elements.

Notice how the d block appears between groups 3 and 4 (13 & 14), rather than between groups 2 and 3 (2 & 13):

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Satz Reciprocal System Periodic Table

Developed in 1971 for my book The Unmysterious Universe, this periodic table is based on Dewey B. Larson's Reciprocal System of theory. The numbers below the symbols indicate the rotational displacement (spin numbers) of the atoms.  The Roman numerals indicated divisions; the rows, 1B to 4B, are referred to as "groups" rather than as "periods."  Note that we have the same trouble positioning hydrogen as does everyone else; here, I've put it over both the alkali metals and the halogens, because it acts both as electropositive (e.g., with respect to water) and electronegative (with respect to carbon).

Click here for larger PDF file.

Ronald W. Satz, Ph.D.
Transpower Corporation

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Elsevier's Periodic Table of the Elements

Prepared by P. Lof is Elsevier's Periodic Table of the Elements.

This educational wall chart features the periodic table of the elements supported by a wealth of chemical, physical, thermodynamical, geochemical and radiochemical data laid down in numerous colourful graphs, plots, figures and tables. The most important chemical and physical properties of the elements can be found - without turning a page.

All properties are presented in the form of tables or graphs. More than 40 properties are given, ranging from melting point and heat capacity to atomic radius, nuclear spin, electrical resistivity and abundance in the solar system. Sixteen of the most important properties are colour coded, so that they may be followed through the periodic system at a glance. Twelve properties have been selected to illustrate periodicity, while separate plots illustrate the relation between properties. In addition, there are special sections dealing with units, fundamental constants and particles, radioisotopes, the Aufbau principle, etc. All data on the chart are fully referenced, and S.I. units are used throughout.

Designed specifically for university and college undergraduates and high school students, "Elsevier's Periodic Table of the Elements" will also be of practical value to professionals in the fields of fundamental and applied physical sciences and technology. The wall chart is ideally suited for self-study and may be used as a complementary reference for textbook study and exam preparation.

Thanks to Eric Scerri for the tip!
See the website and Eric's Twitter Feed

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WebElements: The Periodic Table on The Web

Mark Winter's WebElements was started in 1993 when it was one of the first websites on the internet.

Mark Leach's Chemogenesis web book uses the WebElements periodic table as its master data source, and it does not attempt to duplicate it.

Abundance of elements (Earth's crust)
Abundance of elements (oceans)
Abundance of elements (sun)
Abundance of elements (Universe)
Abundance of elements (in human body)
Accurate mass of the isotopes
Atomic number
Atomic weight
Biological role
Block in periodic table
Boiling point
Bond enthalpy (diatomics)
Bond length in element
Colour (color)
Covalent radius
Crystal structure
Electrical resistivity

Electronic configuration
Element bond length
Enthalpy of atomization
Enthalpy of fusion
Enthalpy of vaporization
Examples of compounds
Group name numbers
Health hazards
History of the element
Ionic radius
Ionization energy
Isotope data
Key data
Meaning of name
Melting point
Molar volume
Names and symbols
Nuclear data
Origin of name

Oxidation states in compounds
Period in table
Properties of some compounds
Radius (atomic)
Radius (covalent)
Radius (ionic)
Radius (van der Waals)
Radius metallic (12)
Radioactive isotopes
Resistivity (electrical)
Shell structure
Standard atomic weights
Standard state
Structure of element
Thermal conductivity
Van der Waals radius
X-ray crystal structure

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Electronegativity Periodic Table

A periodic table showing electronegativity, "The ability of an atom to attract electron density from a covalent bond" (Linus Pauling). Blue elements are electronegative, red elements are electropositive, and purple elements are intermediate. Notice how hydrogen is intermediate in electronegativity between carbon and boron and is positioned above and between these elements:

By Mark Leach

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Electronegativity Periodic Table

"This image distorts the conventional periodic table of the elements so that the greater the electronegativity of an atom, the higher its position in the table", here:

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Extraction from Ore to Pure Element

A periodic table showing how pure elements are extracted:

Highly electropositive elements (Na, K) and electronegative elements (Cl2, F2) can only be obtained by electrolysis.

By Mark Leach

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Where Should Hydrogen Go?

There are four possible positions for hydrogen:

By Mark Leach

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Reaction Chemists' Periodic Table

OK, so which Is The Best formulation of The Periodic Table?

Personally as a reaction chemist, my preferred periodic table is the 'long' form shown below, with hydrogen above and between boron and carbon, although clearly other scientists have other ideas.

All periodic tables show the increase in mass and atomic number, Z, but only the long form unambiguously shows the general top-right-to-bottom-left trends in electronegativity, atomic radius, metallic properties and first ionisation energy.

Electronegativity is absolutely crucial to the understanding of structure, bonding, material type (van Arkel-Ketelaar triangle and Laing tetrahedron) and chemical reactivity, and it underpins much of the chemogenesis analysis.

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Electronegativity Chart (Leach)

From Mark R Leach's paper, Concerning electronegativity as a basic elemental property and why the periodic table is usually represented in its medium form, Journal & PDF.

Due to the importance of Pauling's electronegativity scale, as published in The Nature of The Chemical Bond (1960), where electronegativity ranges from Cs 0.7 to F 4.0, all the other electronegativity scales are routinely normalised with respect to Pauling's range.

When the Pauling, Revised Pauling, Mulliken, Sanderson and Allred-Rochow electronegativity scales are plotted together against atomic number, Z, the similarity of the data can be observed. The solid line shows the averaged data:

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Top 10 Periodic Tables

There are more than 1000 periodic tables hosted by the Chemogenesis Webbook Periodic Table database, so it can be a little difficult to find the exceptional ones.

Here we present – in our humble opinionThe ten most significant periodic tables in the database.

We present the best:

Three Excellent, Data Rich Periodic Tables

The first three of our top 10 periodic tables are classic element data repositories.

They all work in the same way: click on the element symbol to get data/information about the selected element. The three are Mark Winter's WebElements, Theo Gray's Photographic Periodic Table & Michael Dayah's Ptable.

<Web Elements>

Photographic Periodic Table


Five Formulations Showing The History & Development

The next five examples deal with history and development Periodic Table. The first is Dalton's 1808 list of elements, next is Mendeleev's 1869 Tabelle I, then Werner's remarkably modern looking 1905 formulation. This is followed by Janet's Left Step formulation and then a discussion of how and why the commonly used medium form PT formulation, is constructed.

<Eight-Group Periodic Table>

Mendeleev's Tabelle I

Werner's 1905 Periodic Table

Janet's Left Step

modern (and commonly employed) periodic table

electronegativity periodic table

An Alternative Formulation

The internet database contains many, many alternative formulations, and these are often spiral and/or three dimensional. These exemplified by the 1965 Alexander DeskTopper Arrangement. To see the variety of formulations available, check out the Spiral & Helical and 3-Dimensional formulations in the database:

Alexander DeskTopper Arrangement

Non-Chemistry PTs

The periodic table as a motif is a useful and commonly used infographic template for arranging many types of object with, from 50 to 150 members.

There are numerous examples in the Non-Chemistry section where dozens of completely random representations can be found:

Non-Chemistry Periodic Table

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Averaged Ionisation Potential Periodic Table

By Leland Allen, a representation of the periodic table with the third dimension of energy derived from the averaged ionisation potentials of the s and p electrons. (Allen suggested that this was a direct measure of electronegativity). From J. Am. Chem. Soc. 1989, 111, 9004:

Averaged Ionisation Potential

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Acid-Base Behavior of 100 Element Oxides

Acid-Base Behavior of 100 Element Oxides: Visual and Mathematical Representations by Mikhail Kurushkin and Dmitry Kurushkin. J. Chem. Educ.  95, 4, 678-681.

A novel educational chart that represents the acid-base behavior of 100 s-, p-, d-, and f-element oxides depending on the element's electronegativity and oxidation state was designed. An updated periodic table of said oxides was developed. A mathematical criterion based on the chart was derived which allows prediction of the behavior of unfamiliar oxides:

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First Ionisation Energy to the Standard Form Periodic Table

There is debate amongst the cognoscenti about the 'best' representation of the periodic table, and how this 'best' formulation can be explained by [rationalized by] quantum mechanics (QM).

Many feel that the Janet PT formulation, the 'Left Step', is the ideal QM PT, but this formulation does not show periodicity very well, and there are issues with the placement of H, He, Be which spill over into questions about their placement in the standard form PT (the periodic table used in classrooms and textbooks around the world).

However, it is possible to get to the conventional standard form PT directly from the first ionisation energy data, where the 1st ionisation energy is the energy required to convert a gas phase atom (M) into its gas phase positive ion plus electron.

M(g)      →       M+(g)     +     e

The process involves:


Note that a similar logic can be applied to atomic radius and electronegativity data.

However, there are issues about the measurement of atomic radius, because atoms are 'soft at their edges', and gas phase atomic radius is not precisely defined. And, electronegativity is a derived parameter.

By Mark Leach

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Correlation of Electron Affinity (F) with Elemental Orbital Radii (rorb)

From Jour. Fac. Sci., Hokkaido Univ., Ser. IV. vol. 22, no. 2, Aug., 1987, pp. 357-385, The Connection Between the Properties of Elements and Compounds; Mineralogical-Crystallochemical Classification of Elements by Alexander A. Godovikov & Yu Hariya and expanded by René Vernon who writes.

René Vernon writes:

I was delighted to read about two properties that account for nearly everything seen in the periodic table.

Two properties
While researching double periodicity, I happened upon an obscure article, which simply correlates electron affinity with orbital radius, and in so doing reproduces the broad contours of the periodic table. Having never thought much about the value or significance of EA, and its absence of easily discernible trends, I was suitably astonished. The authors left out the Ln and An and stopped at Bi. They were sitting on a gold mine but provided no further analysis.

I added the data up to Lr, updated the EA values, and have redrawn their graph. It is a thing of beauty and wonderment in its simplest sufficient complexity and its return on investment. I've appended 39 observations, covering all 103 elements.


So there it is, just two properties account for nearly everything.

Click images below to enlarge:

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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. 

Click to enlarge:

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What is the Periodic Table Showing? Periodicity

© Mark R. Leach Ph.D. 1999 –

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