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Mineral symbols (text abbreviations) are used to abbreviate mineral groups, subgroups, and species, just as lettered symbols are used for the chemical elements. The first set of commonly used mineral symbols was published in 1983 and covered the common rock-forming minerals using 192 two- or three-lettered symbols. [1]
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 ...
Chemical symbols are the abbreviations used in chemistry, mainly for chemical elements; but also for functional groups, chemical compounds, and other entities. Element symbols for chemical elements, also known as atomic symbols , normally consist of one or two letters from the Latin alphabet and are written with the first letter capitalised.
An illustrative example is the effect of catalysts to speed the decomposition of hydrogen peroxide into water and oxygen: . 2 H 2 O 2 → 2 H 2 O + O 2. This reaction proceeds because the reaction products are more stable than the starting compound, but this decomposition is so slow that hydrogen peroxide solutions are commercially available.
Three numbers immediately following the NMC abbreviation indicate the relative stoichiometry of the three defining metals. For example, an NMC molar composition of 33% nickel, 33% manganese, and 33% cobalt would abbreviate to NMC111 (also NMC333 or NCM333) and have a chemical formula of LiNi 0.33 Mn 0.33 Co 0.33 O 2.
An example of an alkylcobalt complex in the otherwise uncommon +4 oxidation state of cobalt is the homoleptic complex tetrakis(1-norbornyl)cobalt(IV) (Co(1-norb) 4), a transition metal-alkyl complex that is notable for its resistance to β-hydrogen elimination, [29] in accord with Bredt's rule.
Typical catalysts are platinum, and redox-active oxides of iron, vanadium, and molybdenum. In many cases, catalysts are modified with a host of additives or promoters that enhance rates or selectivities. Important homogeneous catalysts for the oxidation of organic compounds are carboxylates of cobalt, iron, and manganese
Also acid ionization constant or acidity constant. A quantitative measure of the strength of an acid in solution expressed as an equilibrium constant for a chemical dissociation reaction in the context of acid-base reactions. It is often given as its base-10 cologarithm, p K a. acid–base extraction A chemical reaction in which chemical species are separated from other acids and bases. acid ...