Trouble in the periodic table
As chemists, we see the periodic table as an icon. But its design continues to evolve and is the source of much debate
The periodic table has been around for almost 140 years and has survived many revolutionary discoveries including that of subatomic structure and the development of quantum mechanics and relativity.
The order of the elements was originally provided by their increasing atomic weights but it was later found that atomic number provided a better ordering principle. For example, the elements tellurium and iodine fell perfectly into place according to their chemical behaviour but their position in the table would have been inverted if ordered strictly by their atomic weights.
Eric Scerri explores the periodic table, in all its forms, its abundance of designs and some problems it faces.
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