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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 1300 Period Tables in the database: 

  Text Search:       

The 10 Periodic Tables most recently added to the database:

1911   Emerson's Periodic Table of Atomic Weights
2020   University of UNAM Periodic Table
2024   Periodic Table Regions
1919   Snyder's Fundamental Periodic Table of The Elements
1995   Considine's Polar Periodic Table
2023   Bala's Shape of the Periodic Table
1936   Van Wert Periodic table (after Guertler-Leitgebel)
2023   Chemdex: Valence & Oxidation Number Trends
2023   Holistic View of Metals & Nonmetals: Exploded View
2023   Semicircular Hybrid Chart of the Nuclides

Year:  1911 PT id = 1296

Emerson's Periodic Table of Atomic Weights

Emerson BK, Helix chemica: A study of the periodic relations of the elements and their graphic representation, American Chemical Journal, vol. 45, pp. 160–210 (1911). The formulation below appears on page 173; a scanned pdf version of the paper can be viewed here.

René Vernon writes:

Emerson includes two elements before hydrogen: "E" (either the luminiferous ether or the electron) and "Coronium". There are also two elements between hydrogen and helium: "Nebulium" and "Protofluorine".

This is the first time I have seen a PT showing four extra elements and where they are supposed to fit.

After La, Emerson incorporates 13 lanthanides (Ce to Lu) as transition elements into his 7th period.

Emerson missed dysprosium, between Tb and Ho.

"A, B and C" at the bottom right are supposed to be 'halogen emanations'.

Mark Leach adds that Emerson's very odd Periodic Table of Atomic Weights does not actually show any atomic weights.

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Year:  2020 PT id = 1295

University of UNAM Periodic Table

Mexico City, University of UNAM Chemistry Department

Thanks to Marcus for the tip!

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Year:  2024 PT id = 1294

Periodic Table Regions

Permanent link to the comic:
Image URL (for hotlinking/embedding):

Thanks to Marcus for the tip!

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Year:  1919 PT id = 1293

Snyder's Fundamental Periodic Table of The Elements

Snyder MB 1919, The Fundamental Periodic Table of the Chemical Elements, filed in Congressional Library, Washington.

René Vernon writes:

"Notable for:

Click to enlarge

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Year:  1995 PT id = 1292

Considine's Polar Periodic Table

From: Considine DM (ed.) 1995, Van Nostrand’s Encyclopedia of Science, 8th ed. New York, p. 2376

René Vernon writes:

"A nice design but of quite limited practical utility for quick reference or detailed chemical analysis."

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Year:  2023 PT id = 1291

Bala's Shape of the Periodic Table

Gavin J. Bala has produced a nice and detailed look at The Shape of The Periodic Table (.PDF) that reviews the science:

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Year:  1936 PT id = 1290

Van Wert Periodic table (after Guertler-Leitgebel)

Van Wert LR, An Introduction to Physical Metallurgy, McGraw-Hill, New York, 1936, pp 17. Van Wert says the periodic table is after "Guertler-Leitgebel", which is presumably Guertler WM & Leitgebel M 1929, Vom Erz zum metallischen Werkstoff: Leitlinien und Rüstzeug der metallurgischen und metallkundlichen Wissensgebiete, Akademische Verlagsgesellschaft, m.b.H., Leipzig

From René Vernon who writes:

In this almost symmetrical presentation, Van Wert divides the periodic table metals into:

Strongly Electropositive:       Groups 1 to 3, Ln
High-melting Heavy Metals:   Transition metals
Low-melting Heavy Metals:    Post-transition metals

If the 15 Rare Earths had been shown as 14, and moved one cell to the left we would have a perfectly symmetrical table.

Elsewhere (p. 38) Van Wert refers to the noble metals as follows:

"With respect to corrosion, the noble metals — gold, the platinum metals, and to a less degree, silver — are in a class by themselves. They are comparatively chemically inert to all common corrodents; only silver is appreciably attacked by sulphur gas."

Van Wert's table also refers to non-metals and to inert gases. On page 7 mention is made of the metalloids:

"There are a few elements, also, that partake of the nature of both metals and nonmetals, under many—indeed, under most—conditions they seem metallic enough, but on occasion their behavior is decidedly nonmetallic. These metalloids, as they are sometimes called, add a further difficulty in the attempt to frame a satisfactory definition of the metallic state."

By 1936, it was known that metalloids had a predominately nonmetallic chemistry (Newth 1894, pp. 7??8; Friend 1914, p. 9). So, on the nonmetal side of house are metalloids; "nonmetals"; and noble gases. Separating out the halogens from the nonmetals yields: metalloids; "nonmetals"; halogens; noble gases.

The net result is four types of metals and four of nonmetals = more symmetry.

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Year:  2023 PT id = 1289

Chemdex: Valence & Oxidation Number Trends

From Mark Winter's review paper Chemdex: quantification and distributions of valence numbers, oxidation numbers, coordination numbers, electron numbers, and covalent bond classes for the elements Dalton Trans., 2024,53, 493-511

The images below show the Valence number (VN) and oxidation number (ON) proportions as percentages for the elements; and Periodic tables displaying valence number proportions (%). (There are few data for Pm and no data for Fr and elements beyond Es.)

The position of H and the group numbers are addressed in the paper.

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Year:  2023 PT id = 1288

Holistic View of Metals & Nonmetals: Exploded View

From Organising the metals and nonmetals: An update by René Vernon from the chemrxiv preprint server.

Rene writes:

Abstract: This paper updates my 2020 article, Organising the metals and nonmetals in which I advocated for parsing the periodic table into four kinds of metals and four of nonmetals. This framework is retained and updated, and augmented with some additional chemistry-related and philosophical observations.

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Year:  2023 PT id = 1287

Semicircular Hybrid Chart of the Nuclides

Nawa Nagayasu has produced a new version of the Segrè Chart of the Nuclides.

Nawa writes:

"The chart has the number of neutrons on the [curved] horizontal axis and the number of protons (atomic number) on the vertical axis. I used the IAEA colour coding [scheme]. JAEA's half-life ranks are indicated by simple numbers, not rounded frames.

"In order to fit the whole chart into a semicircle, the axis representing the number of neutrons was made a spiral-like curve. For clarity, the number of neutrons is shown in the middle of each curve."

Yuri Oganessian has commented:

"Nawa Nagayasu is an original and talented designer. After all, it is not easy to work with 118 elements, but now also with isotopes, of which there are more than 3000. The fan design looks attractive and this is very important. This will make people, especially school age, guess the numbers that are written there. So they will gradually delve into the content of the Table, a truly brilliant creation."

Click image to enlarge

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What is the Periodic Table Showing? Periodicity

© Mark R. Leach Ph.D. 1999 –

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