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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:       


The 8 Periodic Tables most recently added to the database:

2020   Periodic Table Challenge
2017   Restrepo's Similarity Landscape
1950   McCutchon's Simplified Periodic Classification of the Elements
1945   Talpain's Gnomonic Classification of the Elements
2020   Correlation of Electron Affinity (F) with Elemental Orbital Radii (rorb)
1987   Mineralogical-Crystallochemical Classification of Elements
1987   Variation of Orbital Radii with Atomic Number
2020   Vernon's Periodic Table showing the Idealized Solid-State Electron Configurations of the Elements


2020

Periodic Table Challenge

IUPAC have developed a Periodic Table Challenge. Answer PT questions at Beginner, Intermediate or Advanced level.


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2017

Restrepo's Similarity Landscape

Building Classes of Similar Chemical Elements from Binary Compounds and Their Stoichiometries by Guillermo Restrepo, Chapter 5 from: Elements Old and New: Discoveries, Developments, Challenges, and Environmental Implications p 95-110.

From the abstract:

Similarity is one of the key concepts of the periodic table, which was historically addressed by assessing the resemblance of chemical elements through that of their compounds. A contemporary approach to the similarity among elements is through quantum chemistry, based on the resemblance of the electronic properties of the atoms involved. In spite of having two approaches, the historical one has been almost abandoned and the quantum chemical oversimplified to free atoms, which are of little interest for chemistry. Here we show that a mathematical and computational historical approach yields well-known chemical similarities of chemical elements when studied through binary compounds and their stoichiometries; these similarities are also in agreement with quantum chemistry results for bound atoms. The results come from the analysis of 4,700 binary compounds of 94 chemical elements through the definition of neighbourhoods for every element that were contrasted producing similarity classes. The method detected classes of elements with different patterns on the periodic table, e.g. vertical similarities as in the alkali metals, horizontal ones as in the 4th-row platinum metals and mixed similarities as in the actinoids with some transition metals. We anticipate the methodology here presented to be a starting point for more temporal and even more detailed studies of the periodic table.

Lindsay's Periodic Table

Thanks to René for the tip!

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1950

McCutchon's Simplified Periodic Classification of the Elements

McCutchon KB, A simplified periodic classification of the elements, Journal of Chemical Education, vol. 27, no. 1, pp. 17–19 (1950)

This 3-dimensional table has two double-sided flaps attached. The top flap is the f bock. Under that is the d block.

The superscripts denote the number of d electrons an element has. Thus, La1 is shown as being an f1 element. But it has a 1 superscript, meaning that the f electron count is reduced by 1 and the d electron count is 1.

René Vernon writes:

"On group 3, McCutchon cryptically says: The proposed arrangement brings out certain known facts about the tertiary elements which are rarely shown by other arrangements. For example, it suggests, correctly, that the resemblance between yttrium and lutecium is greater than that between yttrium and lanthanum. It classifies lanthanum but not lutecium as a rare earth, in accordance with their chemical properties (which also contradict spectrographic evidence at this point). It also demonstrates the tetravalence of both cerium and thorium, and that thorium and protactinium show a resemblance in chemical properties to zirconium and niobium, as well as to hafnium and tantalum."

I say "cryptically" because McCutchon presents no further evidence in support of his assertion that the resemblance between Y and Lu is greater than between Y and La. He may have had in mind the fact that Lu is more often found in ores of Y than is the case for La... and I don't understand his reference to spectrographic evidence.





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1945

Talpain's Gnomonic Classification of the Elements

Talpain PL 1945, Gnomonic classification of elements, J.Phys. Radium 6, 176-181 (in French), https://doi.org/10.1051/jphysrad:0194500606017600

Talpain writes:

"To overcome the drawbacks presented by the various tables in rows and columns into which the classification of chemical elements is usually inserted, the author proposes a diagram in space, having the form of a double pyramid constructed according to a simple arithmetic law, inspired by Greek surveyors. Under these conditions, all the bodies belonging to the same chemical family are placed on the same column, and all those which have similar physical properties (magnetic, electrical, radioactive, crystallographic, rare earths, etc.) are grouped together. This same diagram also makes it possible to represent the electronic structure of the atoms, the quantified states of the electrons, the energy levels and the spectral lines of hydrogen. Perhaps spectroscopists will be able to use it to also represent the lines of other bodies."

Lindsay's Periodic Table

Thanks to René for the tip!

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2020

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.

Development
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.

Observations

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

Click images below to enlarge:


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1987

Mineralogical-Crystallochemical Classification of Elements

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.

Any mineralogical-crystallochemical classification of elements must provide answers to the following queries:

  1. Which type of compounds certain elements will prefer to form under given conditions of mineral genesis (elementary substance, chalcogenide, oxide, oxysalt, etc.,)
  2. Whether the element will play a role of a cation or anion of a certain valency
  3. Which type of chemical bond the resulting mineral compound will have

Click images below to enlarge:



Thanks to René for the tip!

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1987

Variation of Orbital Radii with Atomic Number

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.

The analyses of the variations of the orbital atomic radii values (rorb) with the increase of the atomic number (Z) allow establishment of the following recurring regularities of their change:

Click image below to enlarge:

Thanks to René for the tip!

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2020

Vernon's Periodic Table showing the Idealized Solid-State Electron Configurations of the Elements

René Vernon writes:

"I've attached a periodic table showing the solid-state electron configurations of the elements. Among other things, it provides a first order explanation as to why elements such as Ln (etc.) like the +3 oxidation state.

"The table includes two versions of the f-block, the first starting with La-Ac; the second with Ce-Th. The table with the first f-block version has 24 anomalies [with respect to Madelung's rule]; the table with the second f-block version has 10 anomalies.

"In the case of the Sc-Y-La-Ac form, I wonder if such a solid-state table is more relevant these days than a table based on gas phase configurations, which has about 20 anomalous configurations.

"Partly we use gas phase configurations since, as Eric Scerri mentioned to me elsewhere, configurations were first obtained (~100 years ago?) from spectroscopy, and this field primarily deals with gas phase atoms. That said, are gas phase configurations still so relevant these days – for this purpose – given the importance of solid-state physics?

"I've never been able to find a periodic table of solid-state electron configurations. Perhaps that has something to do with it? Then again, surely I'm not the first person to have drawn one of these?"

Click image below to enlarge:

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What is the Periodic Table Showing? Periodicity

© Mark R. Leach Ph.D. 1999 –


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