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Cobalt is a chemical element; it has symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, somewhat brittle, gray metal.
The Earth's crust is one "reservoir" for measurements of abundance. A reservoir is any large body to be studied as unit, like the ocean, atmosphere, mantle or crust. Different reservoirs may have different relative amounts of each element due to different chemical or mechanical processes involved in the creation of the reservoir. [1]: 18
Naturally occurring cobalt, Co, consists of a single stable isotope, 59 Co (thus, cobalt is a mononuclidic element). Twenty-eight radioisotopes have been characterized; the most stable are 60 Co with a half-life of 5.2714 years, 57 Co (271.811 days), 56 Co (77.236 days), and 58 Co (70.844 days). All other isotopes have half-lives of less than ...
The compounds cobalt silicate and cobalt(II) aluminate (CoAl 2 O 4, cobalt blue) give a distinctive deep blue color to glass, ceramics, inks, paints and varnishes. Cobalt occurs naturally as only one stable isotope, cobalt-59. Cobalt-60 is a commercially important radioisotope, used as a radioactive tracer and for the production of high-energy ...
The established abundances of chemical elements in urban soils can be considered a geochemical (ecological and geochemical) characteristic, the accumulated impact of technogenic and natural processes at the beginning of the 21st century.
A large fraction of the chemical elements that occur naturally on the Earth's surface are essential to the structure and metabolism of living things. Four of these elements (hydrogen, carbon, nitrogen, and oxygen) are essential to every living thing and collectively make up 99% of the mass of protoplasm. [1]
The nuclides found naturally comprise not only the 286 primordials, but also include about 52 more short-lived isotopes (defined by a half-life less than 100 million years, too short to have survived from the formation of the Earth) that are daughters of primordial isotopes (such as radium from uranium); or else are made by energetic natural ...
In humans most cobalt is found in Vitamin B12.A cobalt atom is visible in the center in this diagram. Cobalt is essential to the metabolism of all animals.It is a key constituent of cobalamin, also known as vitamin B 12, the primary biological reservoir of cobalt as an ultratrace element.