Mendele’ev published the Periodic Table of the Elements in 1869. As a chemistry graduate, I once knew this intimately. It’s not just a classification; it’s a tool for understanding, and for prediction. And the underlying principles were good enough to cope with the discovery of elements Mendele’ev himself had never heard of: radium and uranium for a start (the work of Pierre and Marie Curie), and then all the trans-uranic elements which, on earth at least, have only been created artificially.
Well … a tweet from Frank Zimper (nice to tweet you, Frank, danke!) alerted me to this Periodic Table of the Google elements. I really like it as a chemist as well as an IT practitioner. It doesn’t just categorise; it observes many features of the “real” periodic table, like the groupings (alkali/alkaline earth elements, transition metals, and so on) and even follows the boundary between non-metals and metals in the B group on the right hand side.
Great piece of work! Enjoy it at http://code.google.com/intl/de-DE/more/table/.