Alexandre Beguyer de Chancourtois (1820-1886) oIn 1863, a 44 year old French geologist, he created a list of the elements arranged by increasing atomic weight. The list was wrapped around a cylinder so that several sets of similar elements lined up, creating the first geometric representation of the periodic law. oIn 1862 was the first person to make use of atomic weights to reveal periodicity (i.e. when the elements were arranged according to their atomic weights, similar …showed first 75 words of 345 total…

…showed last 75 words of 345 total…mass units could be written on the cylinder per turn, closely related elements were lined up vertically. This led de Chancourtois to propose that "the properties of the elements are the properties of numbers." De Chancourtois was first to recognize that elemental properties reoccur every seven elements, and using this chart, he was able to predict the the stoichiometry of several metallic oxides. Unfortunately, his chart included some ions and compounds in addition to elements.