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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:       

Year:  1914 PT id = 687

Oddo-Harkins Rule

The Oddo-Harkins rule holds that elements with an even atomic number (such as carbon) are more common than elements with an odd atomic number (such as nitrogen). This effect on the abundance of the chemical elements was first reported by Giuseppe Oddo in 1914 and William Draper Harkins in 1917. See the Wikipedia page:

Oddo-Harkin's rule

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What is the Periodic Table Showing? Periodicity

© Mark R. Leach Ph.D. 1999 –

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