The INTERNET Database of Periodic Tables
There are hundreds of periodic tables in web space, but there is only one 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.
Number of Stable Isotopes by Element
When plotting the number of stable isotopes against element, and against atomic number Z, it is clear that elements with an even atomic number are likely to have more stable isotopes (average 4.9) than elements with an odd atomic number (average 1.3). Click here for the Excel file. There is a Wikipedia page here.
The effect is striking in graphical form:
© Mark R. Leach 1999-
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