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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:  2004 PT id = 143

Biologist's Periodic Tables

A periodic table showing where biologically essential (green), essential trace (purple), toxic (red), radioactive (yellow) and of low – but not zero– biological impact (gray) elements are found. Only highly toxic elements are shown in red. Li (as Li+) is biologically active and is used as an antidepressant.

By Mark Leach

or here:


And a periodic table for biologists from Science Videos:

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What is the Periodic Table Showing? Periodicity

© Mark R. Leach Ph.D. 1999 –

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This free, open access web book is an ongoing project and your input is appreciated.