Scientia: The ever-changing periodic table

Medical Genetics

November 29, 2011     | Author: Freelance Writer Steven A. Edwards, Ph.D.

Because of evolution, we expect biology to be an open-ended subject, but it seems that chemistry should be more constrained.  So how is it that, eleven years into the 21st century, we still don’t have a complete list of the elements?  The most recent formal additions to the Periodic Table of Elements came about in June of this year.  The newest jewels of the realm are unofficially named ununquadium (114) and ununhexium (116).

As everyone learns in Chem 101, the periodic table was first drawn up by Russian chemist Dmitri Mendeleev in 1869.  There were, of course, previous attempts to categorize the elements; Lavoisier published a list of 33 as early as 1789, dividing them into gasses, metals, non-metals and earths, distinctions that are still maintained.  Even the periodicity of the elements had been recognized previously; chemist John…

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