Cobalt twenty-seventh element of the Periodic Table
Cobalt (from German Kobald, pixie, mine demon) is a chemical element, symbol Co, atomic number 27 (27 protons and 27 electrons) and atomic mass 59 u, found at room temperature in the solid state. It is a carbide, ferromagnetic, bluish white in color. Its Curie temperature is 1388 K. It is usually found along with nickel, and both are part of iron meteorites. It is an essential chemical element for mammals in small quantities. Co-60, a radioisotope, is an important cancer tracer and agent.Metal cobalt is usually made up of two allotropic forms with different crystal structures: hexagonal and cubic centered on the faces, with the transition temperature between 722 K.
It has low oxidation states. Compounds in which cobalt has an oxidation state of +4 are uncommon. The oxidation state +2 is very common, as is +3. There are also important complexes with cobalt showing +1 oxidation state.
History:
The element was discovered by Georg Brandt. The date of discovery is uncertain, ranging from 1730 to 1737 in various sources. Brandt was able to demonstrate that cobalt was responsible for the blue staining of glass, which was previously attributed to bismuth. The name of the element comes from the German kobalt or kobold, which means evil spirit or mine demon, so called by the miners because of its toxicity, and the problems it caused were similar to those of nickel, contaminating and degrading the elements you wanted to extract. . Another possible etymology of this word is attributed to the miners Harz and Erzgebirgechitze, who felt misled, since, besides not having the expected value, this metal was harmful to health and silver (metal that occurs along with cobalt); According to legend, miners believed that an elf stole the silver, leaving cobalt in its place.
During the 19th century, between 70 and 80% of world cobalt production was obtained from the Norwegian factory Blaafarveværket of Prussian industrialist Benjamin Wegner.