Jens Jakob Berzelius (Berzelius Jons Jakob)( Swedish chemist.)
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Biography Jens Jakob Berzelius (Berzelius Jons Jakob)
Born August 20, 1779 near Linikepinga in southern Sweden. At the end of the school entered the University of Uppsala. In 1804 received his medical degree and was appointed Adjunct of Medicine and Pharmacy at the University of Stockholm. In 1807 he became a professor of this university, and since 1810 - professor of chemistry at the Medical-Surgical Institute of St.. Carolina. In 1832, left the chair at the institute and began the writing of textbooks and reviews on the chemistry.
Berzelius had a large number of studies that have laid the foundations of many branches of modern chemistry. During 1808-1812, he received new evidence of the law of multiple proportions, previously proposed Dzh.Daltonom, and connected atomic theory with extensive and diverse chemical facts. As a result of long-term studies of various salts, bases and oxides of Berzelius came to the conclusion that the salts are simple and constant relationship between oxygen atoms and oxygen atoms of the base acid. In 1814 he published the table of atomic masses of 41 simple substance, selecting as the unit of comparison, the oxygen atomic weight of which he equated to 100, and in 1818 fully expounded his theory of proportions. By this time he determined the atomic mass of 46 elements and determined the percentage of the 2000 compounds. The results of Berzelius, despite nesovrshenstvo his analytical methods were in many cases close to the modern. With his work on atomism are introducing simple and understandable system of chemical symbols: to describe the element it had adopted the first letter of its Latin or Greek names, . Sometimes it was followed by another letter, to indicate the number of atoms used algebraic codes,
. Berzelius introduced changes in the chemical nomenclature, built it in Latin, and introduced to different classes of compounds relevant prefixes, suffixes and end. Translated into many languages, she served as the basis for the modern chemical nomenclature.
Berzelius is also known for his research in the field of electrochemistry. In 1803 appeared his work on electrolysis (it was carried out jointly with V. hisingerite), in 1812 - on the classification of electrochemical elements, and in 1818 was formulated electrochemical theory. The basis of the theory lay the assumption that the polar structure of atoms: it was believed that the electrical charges of both signs are present on the atoms to their ground (in contrast to H. Davy, who believed that atoms are electrified by contact). By the nature of the prevailing charge on atoms Berzelius distinguished between electronegative and electropositive elements and divided the known at the time 56 parts into two classes, . based on the properties of which they form compounds with the most electronegative element - oxygen,
. Thus was obtained by the electrochemical series of elements and the unit of metals and metalloids. Electrochemical theory formed the basis of a dualistic system created by Berzelius to establish rational formulas of chemical compounds. Based on data obtained during the electrolysis of different salt solutions, Berzelius assumed that all salts contain the base and acid. This theory has stimulated numerous studies, but, assuming the existence of only the oxygen acids, proved to be untenable when applied to organic compounds. The term 'organic chemistry' is also introduced Berzelius (1806). In 1811 he began a systematic investigation of elemental composition of organic compounds in 1815 led the formula of acetic, succinic, tartaric, etc.. acids. Studying the acid of grapes in 1830, found that the composition is identical to the wine and offered to explain the differences in their properties of unequal distribution of atoms. To describe this phenomenon suggested the term 'isomer'. In addition, Berzelius introduced such important concepts as catalysis and allotropy.
Extensive work Berzelius also included a study on the analytical and inorganic chemistry, work on the mineralogy. He undertook a systematic study of many ores, proposed chemical classification of minerals. As the author of a new mineralogy of the Royal Society awarded him the Copley Medal in 1836. He developed new methods of qualitative (test for arsenic) and quantitative analysis, perfected many of the instruments and created a new. Inorganic Chemistry obliged Berzelius discovery of many elements: Cerium (1803), selenium (1817), silicon (1824), zirconium (1824), tantalum (1825), vanadium (1830).
In 1808 Berzelius was a member of the Swedish Academy of Sciences, in 1810 - its President, and in 1818 - Permanent Secretary. In 1818 he was knighted, in 1835 he was granted the title of Baron. Died Berzelius in Stockholm on Aug. 7, 1848.