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Ditellurium Decafluoride
Ditellurium decafluoride was widely reported in the literature but what was believed to be Te2F10 has been shown to be teflic anhydride, F5TeOTeF5. An account as to how this error occurred was made by P. M. Watkins. If it existed, it would be valence isoelectronic with disulfur decafluoride Disulfur decafluoride is a chemical compound with the formula . It was discovered in 1934 by Kenneth Denbigh, Denbigh and Whytlaw-Gray. Each sulfur atom of the molecule is octahedral, and surrounded by five fluorine atoms and one sulfur atom. The ..., and have a similar structure. References Tellurium compounds Fluorides Nonmetal halides Chalcohalides Hypothetical chemical compounds {{Hyp-chem-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Literature
Literature is any collection of written work, but it is also used more narrowly for writings specifically considered to be an art form, especially prose fiction, drama, and poetry. In recent centuries, the definition has expanded to include oral literature, much of which has been transcribed. Literature is a method of recording, preserving, and transmitting knowledge and entertainment, and can also have a social, psychological, spiritual, or political role. Literature, as an art form, can also include works in various non-fiction genres, such as biography, diaries, memoir, letters, and the essay. Within its broad definition, literature includes non-fictional books, articles or other printed information on a particular subject.''OED'' Etymologically, the term derives from Latin ''literatura/litteratura'' "learning, a writing, grammar," originally "writing formed with letters," from ''litera/littera'' "letter". In spite of this, the term has also been applied to spok ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teflic Acid
Teflic acid is the chemical compound with the formula . This strong acid is related to orthotelluric acid, . Teflic acid has a slightly distorted octahedral geometry. Preparation Teflic acid was accidentally discovered by Engelbrecht and Sladky. Their synthesis did not yield the anticipated telluryl fluoride , but a mixture of volatile telluric compounds, ''i.e.'' :Engelbrecht, A.; Sladky, F. "Pentafluoro-orthotellursaure, " ''Angewandte Chemie'' 1964. ''76''(9), 379-380, . : (25%) Teflic acid can also be prepared from fluorosulfonic acid and barium tellurate:Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. . : It is also the first hydrolysis product of tellurium hexafluoride: : Teflates The conjugate base of teflic acid is called the teflate anion, (not to be confused with triflate). Many teflates are known, examples being and the acid anhydride . Pyrolysis of the boron compound gives the dimer . : The teflate anion is known to resist oxi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Error
An error (from the Latin ''error'', meaning "wandering") is an action which is inaccurate or incorrect. In some usages, an error is synonymous with a mistake. The etymology derives from the Latin term 'errare', meaning 'to stray'. In statistics, "error" refers to the difference between the value which has been computed and the correct value. An error could result in failure or in a deviation from the intended performance or behavior. Human behavior One reference differentiates between "error" and "mistake" as follows: In human behavior the norms or expectations for behavior or its consequences can be derived from the intention of the actor or from the expectations of other individuals or from a social grouping or from social norms. (See deviance.) Gaffes and faux pas can be labels for certain instances of this kind of error. More serious departures from social norms carry labels such as misbehavior and labels from the legal system, such as misdemeanor and crime. Departures ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoelectronicity
Isoelectronicity is a phenomenon observed when two or more molecules have the same structure (positions and connectivities among atoms) and the same electronic configurations, but differ by what specific elements are at certain locations in the structure. For example, , , and are isoelectronic, while and = are not. This definition is sometimes termed ''valence isoelectronicity''. Definitions can sometimes be not as strict, sometimes requiring identity of the ''total'' electron count and with it the entire electronic configuration. More usually, definitions are broader, and may extend to allowing different numbers of atoms in the species being compared.A. A. Aradi & T. P. Fehlner, "Isoelectronic Organometallic Molecules", in F. G. A. Stone & Robert West (eds.) ''Advances in Organometallic Chemistry Vol. 30'' (1990), Chapter 5 (at p. 190google books link/ref> The importance of the concept lies in identifying significantly related species, as pairs or series. Isoelectron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disulfur Decafluoride
Disulfur decafluoride is a chemical compound with the formula . It was discovered in 1934 by Kenneth Denbigh, Denbigh and Whytlaw-Gray. Each sulfur atom of the molecule is octahedral, and surrounded by five fluorine atoms and one sulfur atom. The two sulfur atoms are connected by a single bond. In the molecule, the oxidation state of each sulfur atoms is +5, but their Valence (chemistry), valency is 6 (they are hexavalent). is highly toxic, with toxicity four times that of phosgene. It is a colorless liquid with a burnt match smell similar to sulfur dioxide. Production Disulfur decafluoride is produced by photolysis of : : Disulfur decafluoride arises by the decomposition of sulfur hexafluoride. It is produced by the electrical decomposition of sulfur hexafluoride ()—an essentially inert Electrical insulation, insulator used in high voltage systems such as transmission lines, Electrical substation, substations and switchgear. is also made during the production of . Propert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tellurium Compounds
Tellurium compounds are compounds containing the element tellurium (Te). Tellurium belongs to the chalcogen (group 16) family of elements on the periodic table, which also includes oxygen, sulfur, selenium and polonium: Tellurium and selenium compounds are similar. Tellurium exhibits the oxidation states −2, +2, +4 and +6, with +4 being most common. Tellurides Reduction of Te metal produces the Telluride (chemistry), tellurides and polytellurides, Ten2−. The −2 oxidation state is exhibited in binary compounds with many metals, such as zinc telluride, , produced by heating tellurium with zinc. Decomposition of with hydrochloric acid yields hydrogen telluride (), a highly unstable analogue of the other chalcogen hydrides, Water (molecule), , Hydrogen sulfide, and Hydrogen selenide, : is unstable, whereas salts of its conjugate base [TeH]− are stable. Halides The +2 oxidation state is exhibited by the dihalides, , and . The dihalides have not been obtained in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorides
Fluoride (). According to this source, is a possible pronunciation in British English. is an inorganic, monatomic anion of fluorine, with the chemical formula (also written ), whose salts are typically white or colorless. Fluoride salts typically have distinctive bitter tastes, and are odorless. Its salts and minerals are important chemical reagents and industrial chemicals, mainly used in the production of hydrogen fluoride for fluorocarbons. Fluoride is classified as a weak base since it only partially associates in solution, but concentrated fluoride is corrosive and can attack the skin. Fluoride is the simplest fluorine anion. In terms of charge and size, the fluoride ion resembles the hydroxide ion. Fluoride ions occur on Earth in several minerals, particularly fluorite, but are present only in trace quantities in bodies of water in nature. Nomenclature Fluorides include compounds that contain ionic fluoride and those in which fluoride does not dissociate. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nonmetal Halides
In chemistry, a nonmetal is a chemical element that generally lacks a predominance of metallic properties; they range from colorless gases (like hydrogen) to shiny solids (like carbon, as graphite). The electrons in nonmetals behave differently from those in metals. With some exceptions, those in nonmetals are fixed in place, resulting in nonmetals usually being poor conductors of heat and electricity and brittle or crumbly when solid. The electrons in metals are generally free moving and this is why metals are good conductors and most are easily flattened into sheets and drawn into wires. Nonmetal atoms tend to attract electrons in chemical reactions and to form acidic compounds. Two nonmetals, hydrogen and helium, make up about 99% of ordinary matter in the observable universe by mass. Five nonmetallic elements, hydrogen, carbon, nitrogen, oxygen and silicon, largely make up the Earth's crust, atmosphere, oceans and biosphere. Most nonmetals have biological, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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