Eric Scerri, a UCLA chemistry lecturer, has written at least six books discussing the orientation of the periodic table. His office is cluttered with posters and three-dimensional models of different periodic systems. Read more...
Photo: The left step periodic table places helium with highly reactive elements such as magnesium and calcium instead of in the rightmost column with the other less reactive elements. (Creative Commons photos by Valery Tsimmerma and Dmarcus100 via Wikimedia Commons)





