History of the periodic table Essay

Alexandre Beguyer de Chancourtois (1820-1886)In 1863, a 44 year old French geologist, he created a hear of the elements arranged by increasing atomic weight. The list was wrapped virtually a cylinder so that several sets of similar elements lined up, creating the get-go geometric representation of the periodic law.In 1862 was the setoff person to run use of atomic weights to reveal periodicity (i.e. when the elements were arranged according to their atomic weights, similar elements seemed to occur at regular intervals.) He drew the elements as a continuous spiral around a cylinder dissever into 16 parts. The atomic weight of oxygen was taken as 16 and used as the standard against which all others were compared. Chancourtois noticed that certain of the triads appeared infra one another in his spiral. In particular the tetrad oxygen, sulfur, atomic number 34 and tellurium fell together, and he called his device the telluric helix.The atomic weights of these elements are 16,32 ,79 and 128, respectively, and quite fortuitously they are multiples or near multiples, of 16. former(a) parts of the screw were less successful. Thus boron and aluminium hang together all right but are then followed by nickel, arsenic, lanthanum and palladium. Chancourtois had discovered periodicity, but had got the frequency wrong.If a periodic board is regarded as an ordering of the chemical elements demonstrating the periodicity of chemical and physical properties, assent for the first periodic t fit (published in 1862) probably should be condition to a French geologist, A.E.Beguyer de Chancourtois. De Chancourtois transcribed a list of the elements positioned on a cylinder in terms of increasing atomic weight. When the cylinder was constructed so that 16 mass units could be written on the cylinder per turn, fast 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 wa s 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 inaddition to elements.