Kobalt / Cobalt (Co)

Kobalt je hemijski  element atomskog (rednog) broja 27. U periodnom sistemu elemenata predstavlja ga simbol Co. Kobalt je čeličnosive boje, vrlo tvrd, žilav i otrovan metal. 

Godine 1735. švedski hemičar Georg Brandt otkrio je do tada nepoznati element i dao mu ime kobalt. Simbol "Co" je izveden od dva početna slova latinskog naziva za kobalt - Cobaltum.

Kobalt se nalazi u mnogim rudama. Koristi se za legure koje trebaju biti magnetične, otporne na koroziju i jako čvrste. Važan je sastojak u industriji boja, tinta i lakova. Često je povezan s niklom. Sisavci zahtijevaju male količine kobaltove soli. Izotop Co60 (umjetno proizveden radioaktivni izotop kobalta) važan je radioaktivni traser i upotrebljava se u medicinskoj radioterapiji pri liječenju tumora i oboljelih od karcinoma. Metalni kobalt često predstavlja mješavinu dvije kristalografske strukture. Česta oksidacijska stanja su mu +2, +3, ali postoji i kobalt s oksidacijskim stanjem +1.

Cobalt is a chemical element of atomic (ordinal) number 27. In the periodic table of elements is represented by the symbol Co. Cobalt is a steel-gray color, a very hard, tough, ferromagnetic and poisonous metal. 

In 1735, the Swedish chemist Georg Brandt discovered a hitherto unknown element and gave it the name cobalt. The symbol "Co" is derived from the two initial letters of the Latin name for cobalt - Cobaltum. 

Cobalt is found in many ores. It is used for alloys that need to be magnetic, wear-resistant and very strong. It is an important ingredient in the paint, ink and varnish industry. It is often associated with nickel.  Mammals require small amounts of cobalt salt. Cobalt has a relative permeability equal to two-thirds of the permeability of iron. Metallic cobalt is often a mixture of two crystallographic structures. Its frequent oxidation states are +2, +3, but there is also cobalt with an oxidation state of +1.