History Periodic Tabel

HISTORY OF THE PERIODIC TABLE It was 1649 when the scientist Hennig Brand discovered the kickoff element, phosphoric and by 1869 a total of 63 elements had been discovered. As the total of elements discovered increased scientists started to see patterns in their properties and they began to path a way of classifying the elements. Between around 1770 and 1789Antoine Lavoisier wrote the first solely-encompassing angle of dip of 33 elements, however, it was discovered posterior on that some were real mixtures and compounds rather than elements. In 1828, the Swedish apothecary Jöns Jacob Berzelius compiled a table of relative nuclear free weights of all the elements that had been discovered up to this time. Berzelius similarly developed the system of apply letters to typify elements which is still apply to this day, eg: O is used to represent oxygen. Johann Dobereiner first noticed in 1817 that the atomic weight of Strontium was surrounded by the atomic weights of calcium and atomic number 56 which had similar chemical properties. It was this that later led Johann Dobereiner, in 1829 to contrive the Law of the Triads, after discovering the halogen and root word metals triad. The English apothecary John Newlands arranged the known elements in order of atomic weights and grouped them into 11 groups according to the similarities in their physical properties. In 1864 he proposed the Law of the Octaves where he discovered similarities in pairs of elements that occurred betwixt the first and ninth element and the bet on and the tenth part element etc. Lothar Meyer, in 1869, compiled the semiannual table so that the elements were arranged in order of atomic mass so to show elements that had similar chemical and physical properties were grouped to accepther at various intervals in the periodic table. In 1869, Dmitri Mendeleev also compiled the periodic table with the 63 known elements by organization them in order of ascending atomic wei ght and sort come in to halther the elemen! ts with similar properties. His table left gaps fro elements...If you want to get a full essay, order it on our website: BestEssayCheap.com

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