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Jöns Jacob Berzelius

Jöns Jacob  Berzelius

 c

   

       
 Väfersunde-Sörgåid 20.August.1779 - Stoccolma 7.August.1848
1817 Sélénium
 

       
Chemical, which in 1817 isolate selenium fundamental component for the development of the cells of photo-electric stations and successive occasions for television.
  


       

Biographical notes





Swedish Chemicals Berzelius as a poor family.  Was able to study medicine at Uppsala. Following did volunteer assistant in Stockholm in the faculty of medicine.  A. Shortly after the invention of A. Volta's battery.  In 1802 began his chemical experiments on the effects of electrical current (W. Nicholson), having by 1803 in its collaboration with W. Hisinger that all salts are decomposed electrical. From here developed its dualistic conception (see below) according to which all inorganic or organic compounds are made up of positive and negative components.  In 1803, again with the help of Hisinger, discovered the cerium, which was later followed the discovery of selenium and thorium. Berzelius Isolated for the first, silicon, zirconium and titanium.

Base is on the assumption that the smallest particles of a substance simply have a well-defined electrical polarity.  But in each electricity pole and electricity negative positive do not have the same strength.  Depending on whether one or other domains, the substance is electro positive or electronegative. Substances electro positive buy electricity always positive when you join with a substance electronegative. B. Chemical elements divided into two broad classes and sign suppose that the power consumption of each item could change depending on the compound where entered. Only oxygen was invariably negative.  In this classification the items were ordered following the progression of their properties positive, those around the middle of progression electrochemical properties were not clearly defined.  In this way each was composed by the elements or groups of elements of electric opposite sign.  This representation was adopted universally.  It remained unchanged in inorganic chemistry, even if the progress made in organic chemistry exceeded (where anyway B. anticipated the idea of radical).

= J. Convinced supporter of the theory of atomic J. Dalton, Berzelius  Wanted to check and compare the various positions on the presence of fixed proportions between components of a compound and no (GEL Proust = e = C.-L. Berthollet) by a huge number of chemical analyzes conducted on more than 2000 compounds (1807 -- 17) and in which demonstrated extraordinary analytical ability. Berzelius,  who in 1815 was appointed professor of chemistry at the Institute of Medical and surgical Stockholm (retired in 1832), knew how to find an agreement between the theory atomistic that of fixed proportions and concepts on the role of the combustion (AL = Lavoisier), building a table of atomic weights, using oxygen as a base (which attributed the weight 100). In 1818 he published the table of atomic weights of 45 of 49 chemical elements then known table perfected and expanded in 1828.  Berzelius During these searches, developed its system of chemical nomenclature. Berzelius Chose as a symbol of the first letter or  Latin name of each element, to avoid confusion and misunderstandings in the case of ambiguity, the first letter was followed by a letter.  Also obtained the formula of the substance composed.
Which the symbols were accompanied by representatives corresponding numerical units atomic weight of each constituent element the compound. The principle of this notation has never been abandoned.

He invented the term to describe catalysis of the phenomenon associated with the acceleration of the rate of chemical processes (catalytic action is Acids hydrolysis discovery of starch from GR = Kirchhoff, as well as that of platinum sponge electrolyze) .  The bonds between atoms or groups of atoms in molecules were coulombian origin. She chose hydrogen as a reference in determining the equivalent weights and introduced the concept of isomeric (name that dates back to B.) and allotropic. Studied proteins (again will propose the name, derived from the greek prèteioj, "Primary "to indicate the key role for life).  Improvement significantly from what was great analyst, instrumentation, chemical laboratory (inter alia: paper for filtering, rubber tubes, pipettes of technique, balance). In recent years the controversy with the chemical younger He make bitter deeply.

The entire career of Berzelius Took place in Stockholm and in his laboratory worked almost all chemical Germans who bought reputation in the nineteenth century. The prestige of its work, the annual reviews in which presented and commented on the critical work of his staff made him a true legislator chemistry.  His masterpiece is the wording of the dualistic theory and the chemistry of symbolism that later would have a considerable importance not only for the chemical language, but also in the representation and discussion of any reaction. The great Swedish scientist exercised an unopposed on the development of the chemical for about 30 years.