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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: 

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Year:  2001 PT id = 1062

Gorbunov and Filippov's Doubled Periodic Table

Gorbunov, A. I., Filippov, G. G.: Fine Structure of D. I. Mendeleev Periodic Table: secondary periodicity, early and late elements. Khim-ya Tekhnol. 11, 43–45 (2001). (in Russian)

Naum S. Imyanitov (Foundations of Chemistry) writes:

"The two-table design is of particular interest. Atoms with odd n+l are located in the upper table, and the ones with even n+l are placed in the bottom table (Tables 5). The elements are divided by a vertical line of symmetry to the early and late ones both in the upper and bottom tables. The advantage of Tables 5 is a clear demarcation into subsets, with each subset having its own separate place in the table. The drawback is directly related to this advantage: this table does not reflect the similarity between members of different subsets."

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What is the Periodic Table Showing? Periodicity

© Mark R. Leach Ph.D. 1999 –

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