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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:

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Periodic Tables from the year 1937:

1937   Pozzi's Spiral Periodic Table
1937   Zmaczynski's Fan-Shaped System
1937   Discovery of Technetium
1937   Geochemical Periodic Table (Goldschmidt Classification)


Pozzi Spiral Periodic Table

A spiral periodic table formulation constructed by E.C. Pozzi in 1937, from here.

Note the "Strong Positive, Strong Negative, Weak Positive and Weak Negative" corners:

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Zmaczynski's Fan-Shaped System

Zmaczynski's fan-shaped system of 1937 (from van Spronsen):

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Discovery of Technetium


Technetium, atomic number 43, has a mass of 98 au.

Radioactive element: Tc is only found in tiny amounts in nature. Most samples are synthetic.

Technetium was first isolated in 1937 by C. Perrier and E. Segrè. The element had been predicted by Mendeleev in 1871 as eka-manganese.

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Geochemical Periodic Table (Goldschmidt Classification)

From Wikipedia: The Goldschmidt Classification is a gechemical periodic table which groups the chemical elements within the Earth according to their preferred host phases into:

Some elements have affinities to more than one phase. The main affinity is given in the table below and a discussion of each group follows that table.

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What is the Periodic Table Showing? Periodicity

© Mark R. Leach Ph.D. 1999 –

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