History of the periodic table Essay

Alexandre Beguyer de Chancourtois (1820-1886)In 1863, a 44 year old french geologist, he created a list of the elements set up by increasing atomic weight. The list was wrap around a cylinder so that several sets of similar elements lined up, creating the front geometric representation of the periodic law.In 1862 was the head start person to make engross of atomic weights to reveal cyclicity (i.e. when the elements were arranged according to their atomic weights, similar elements seemed to do at regular intervals.) He pull the elements as a continuous reel around a cylinder carve up into 16 separate. The atomic weight of atomic number 8 was taken as 16 and employ as the standard against which all(a) others were comp ard. Chancourtois sight that certain of the triads appeared below one another(prenominal) in his spiral. In particular the quaternity oxygen, sulfur, selenium and tellurium fell together, and he called his device the telluric helix.The atomic weights of the se elements are 16,32,79 and 128, respectively, and quite fortuitously they are multiples or near multiples, of 16. Other parts of the screw were less successful. Thus barn and aluminium come together all right that are thence followed by nickel, arsenic, lanthanum and palladium. Chancourtois had discovered periodicity, but had got the frequency wrong.If a periodic plug-in is regarded as an ordering of the chemical elements demonstrating the periodicity of chemical and physical properties, credit for the first periodic table (published in 1862) plausibly should be given to a French geologist, A.E.Beguyer de Chancourtois. De Chancourtois transcribed a list of the elements positioned on a cylinder in legal injury of increasing atomic weight. When the cylinder was constructed so that 16 mass units could be indite on the cylinder per turn, closely related to elements were lined up vertically. This led de Chancourtois to extend that the properties of the elements are the propertie s of numbers. De Chancourtois was first to recognize that main(a) 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.