Back view of a bust of Jons Jacob Berzelius (1779-1848), the Swedish chemist. It is made of selenium, a non-metallic element occurring naturally in various metallic suphide ores and characterized by the variation of its electrical resistivity with intensity of illumination. Berzelius discovered selenium in Sweden in 1817, and was also responsible for the discovery of two other elements, cerium and thorium. He also was the first to introduce modern chemical symbols, devised the first consistently accurate method of using the oxidation technique developed by Gay-Lusac and Thenard, which allowed surveys of organic composition to be made. His accurate determination of atomic weights established the laws of combination and Dalton's atomic theory.
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