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: Dr Mark R Leach.
Use the buttons below to select from the 1000+ Periodic Tables in the database:
Discovery of Selenium
Selenium, atomic number 34, has a mass of 78.971 au.
Selenium was first isolated in 1817 by J. Berzelius and G. Gahn.
© Mark R. Leach 1999-
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