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J̦ns Jacob Berzelius (August 20, 1779 - August 7, 1848) was a Swedish chemist. He worked out the modern technique of chemical formula notation, and is considered a father of modern chemistry. In 1828 he compiled a table of relative atomic weights, where oxygen was set to 100, and which included all of the elements known at the time. This work provided evidence in favor of the atomic theory proposed by John Dalton: that inorganic chemical compounds are composed of atoms combined in whole number amounts. In discovering that atomic weights are not integer multiples of the weight of hydrogen, he also disproved Prout's hypothesis that elements are built up from atoms of hydrogen. In order to aid his experiments, he developed a system of chemical notation in which the elements were given simple written labels with proportions noted by numbers. This is the same basic system used today. Berzelius is credited with identifying the chemical elements silicon, selenium, thorium, and cerium.
