Search results
Results from the WOW.Com Content Network
Cobalt is also used in the petroleum industry as a catalyst when refining crude oil. This is to purge it of sulfur, which is very polluting when burned and causes acid rain. [11] Cobalt is the active center of a group of coenzymes called cobalamins. Vitamin B 12, the best-known example of the type, is an essential vitamin for all animals.
A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [ 1 ] The definitive visualisation of all 118 elements is the periodic table of the elements , whose history along the principles of the periodic law was one of the founding ...
This is a list of chemical elements and their atomic properties, ordered by atomic number (Z).. Since valence electrons are not clearly defined for the d-block and f-block elements, there not being a clear point at which further ionisation becomes unprofitable, a purely formal definition as number of electrons in the outermost shell has been used.
Cobalt-60 (60 Co) is a synthetic radioactive isotope of cobalt with a half-life of 5.2714 years. [ 3 ] [ 4 ] : 39 It is produced artificially in nuclear reactors . Deliberate industrial production depends on neutron activation of bulk samples of the monoisotopic and mononuclidic cobalt isotope 59
The atomic number or nuclear charge number (symbol Z) of a chemical element is the charge number of its atomic nucleus. For ordinary nuclei composed of protons and neutrons , this is equal to the proton number ( n p ) or the number of protons found in the nucleus of every atom of that element.
Electron affinity / ... Cobalt 27 Co 58.933: Nickel 28 Ni ... Atoms with the same number of protons but different numbers of neutrons are called isotopes of the same ...
Period 5 has the same number of elements as period 4 and follows the same general structure but with one more post transition metal and one fewer nonmetal. Of the three heaviest elements with biological roles, two (molybdenum and iodine) are in this period; tungsten, in period 6, is heavier, along with several of the early lanthanides.
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 ...