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What is the Periodic Table Showing? Periodicity

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. The database holds information on periodic tables, the discovery of the elements, the elucidation of atomic weights and the discovery of atomic structure (and much, much more).

   Use the drop menus or search box (below) to Select or Search the 1400 entries in the database: 

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Year:  1937 PT id = 823, Type = element

Discovery of Technetium

Tc

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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What is the Periodic Table Showing? Periodicity

© Mark R. Leach Ph.D. 1999 –


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