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Magnesium Polonide
Magnesium polonide (MgPo) is a salt of magnesium and polonium. It is a polonide, a set of very chemically stable compounds of polonium. Preparation Magnesium polonide can be produced by heating a mixture of elemental magnesium and polonium at 300–400 °C. Structure Magnesium polonide has the nickeline (NiAs) structure. It is unusual among polonides in not being isomorphous with the corresponding sulfide, selenide A selenide is a chemical compound containing a selenium anion with oxidation number of −2 (Se2−), much as sulfur does in a sulfide. The chemistry of the selenides and sulfides is similar. Similar to sulfide, in aqueous solution, the selenide ion ... and telluride; only mercury polonide (HgPo) shares this property. References {{inorganic-chemistry-stub Magnesium compounds Polonides Nickel arsenide structure type ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Physical Chemistry
''The Journal of Physical Chemistry A'' is a scientific journal which reports research on the chemistry of molecules - including their dynamics, spectroscopy, kinetics, structure, bonding, and quantum chemistry. It is published weekly by the American Chemical Society. Before 1997 the title was simply ''Journal of Physical Chemistry''. Owing to the ever-growing amount of research in the area, in 1997 the journal was split into ''Journal of Physical Chemistry A'' (molecular theoretical and experimental physical chemistry) and '' The Journal of Physical Chemistry B'' (solid state, soft matter, liquids, etc.). Beginning in 2007, the latter underwent a further split, with ''The Journal of Physical Chemistry C'' now being dedicated to nanotechnology, molecular electronics, and related subjects. Editors-in-chief *1896–1932 Wilder Dwight Bancroft, Joseph E. Trevor *1933–1951 S. C. Lind *1952–1964 William A. Noyes *1965–1969 F. T. Wall *1970–1980 Bryce Crawford *1980–2004 Mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Chemical Society
The American Chemical Society (ACS) is a scientific society based in the United States that supports scientific inquiry in the field of chemistry. Founded in 1876 at New York University, the ACS currently has more than 155,000 members at all degree levels and in all fields of chemistry, chemical engineering, and related fields. It is one of the world's largest scientific societies by membership. The ACS is a 501(c) organization, 501(c)(3) non-profit organization and holds a congressional charter under Title 36 of the United States Code. Its headquarters are located in Washington, D.C., and it has a large concentration of staff in Columbus, Ohio. The ACS is a leading source of scientific information through its peer-reviewed scientific journals, national conferences, and the Chemical Abstracts Service. Its publications division produces over 60 Scientific journal, scholarly journals including the prestigious ''Journal of the American Chemical Society'', as well as the weekly tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nickeline
Nickeline or niccolite is a mineral consisting primarily of nickel arsenide (NiAs). The naturally-occurring mineral contains roughly 43.9% nickel and 56.1% arsenic by mass, but composition of the mineral may vary slightly. Small quantities of sulfur, iron and cobalt are usually present, and sometimes the arsenic is largely replaced by antimony. This last forms an isomorphous series with breithauptite (nickel antimonide). Etymology and history Medieval miners looking for copper in the German Erzgebirge ("Ore Mountains") would sometimes find a red mineral, superficially resembling copper ore. Upon attempting extraction, no copper was produced, and subsequently, the miners would be afflicted with mysterious illness. They blamed a mischievous sprite of German mythology, Nickel (similar to ''Old Nick'') for besetting the copper (German: Kupfer). This German equivalent of "copper-nickel" was used as early as 1694 (other old German synonyms are ''Rotnickelkies'' and ''Arsennickel' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pearson Symbol
The Pearson symbol, or Pearson notation, is used in crystallography as a means of describing a crystal structure, and was originated by W. B. Pearson. The symbol is made up of two letters followed by a number. For example: * Diamond structure, ''cF''8 * Rutile structure, ''tP''6 The two (italicised) letters specify the Bravais lattice. The lower-case letter specifies the crystal family, and the upper-case letter the centering type. The number at the end of the Pearson symbol gives the number of the atoms in the conventional unit cell.Nomenclature of Inorganic Chemistry IUPAC Recommendations 2005 IR-3.4.4, pp. 49–51; IR-11.5, pp. 241–242. |
Magnesium
Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic table) it occurs naturally only in combination with other elements and it almost always has an oxidation state of +2. It reacts readily with air to form a thin passivation coating of magnesium oxide that inhibits further corrosion of the metal. The free metal burns with a brilliant-white light. The metal is obtained mainly by electrolysis of magnesium salts obtained from brine. It is less dense than aluminium and is used primarily as a component in strong and lightweight alloys that contain aluminium. In the cosmos, magnesium is produced in large, aging stars by the sequential addition of three helium nuclei to a carbon nucleus. When such stars explode as supernovas, much of the magnesium is expelled into the interstellar medium where it ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polonium
Polonium is a chemical element with the symbol Po and atomic number 84. Polonium is a chalcogen. A rare and highly radioactive metal with no stable isotopes, polonium is chemically similar to selenium and tellurium, though its metallic character resembles that of its horizontal neighbors in the periodic table: thallium, lead, and bismuth. Due to the short half-life of all its isotopes, its natural occurrence is limited to tiny traces of the fleeting polonium-210 (with a half-life of 138 days) in uranium ores, as it is the penultimate daughter of natural uranium-238. Though slightly longer-lived isotopes exist, they are much more difficult to produce. Today, polonium is usually produced in milligram quantities by the neutron irradiation of bismuth. Due to its intense radioactivity, which results in the radiolysis of chemical bonds and radioactive self-heating, its chemistry has mostly been investigated on the trace scale only. Polonium was discovered in July 1898 by Marie SkÅ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polonide
A polonide is a chemical compound of the radioactive element polonium with any element less electronegative than polonium. Polonides are usually prepared by a direct reaction between the elements at temperatures of around 300–400 °C... They are amongst the most chemically stable compounds of polonium,. and can be divided into two broad groups: *ionic polonides, which appear to contain the Po2− anion; *intermetallic polonides, in which the bonding is more complex. Some polonides are intermediate between these two cases and others are non-stoichiometric compounds. Alloys containing polonium are also classed as polonides. As polonium is immediately below tellurium in the periodic table, there are many chemical and structural similarities between polonides and tellurides. Naturally occurring polonides Lead polonide (PbPo) occurs naturally, as lead is produced in the alpha decay of polonium. Ionic polonides The polonides of the most electropositive metals show classic ionic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Academic Press
Academic Press (AP) is an academic book publisher founded in 1941. It was acquired by Harcourt, Brace & World in 1969. Reed Elsevier bought Harcourt in 2000, and Academic Press is now an imprint of Elsevier. Academic Press publishes reference books, serials and online products in the subject areas of: * Communications engineering * Economics * Environmental science * Finance * Food science and nutrition * Geophysics * Life sciences * Mathematics and statistics * Neuroscience * Physical sciences * Psychology Well-known products include the ''Methods in Enzymology'' series and encyclopedias such as ''The International Encyclopedia of Public Health'' and the ''Encyclopedia of Neuroscience''. See also * Akademische Verlagsgesellschaft (AVG) — the German predecessor, founded in 1906 by Leo Jolowicz (1868–1940), the father of Walter Jolowicz Walter may refer to: People * Walter (name), both a surname and a given name * Little Walter, American blues harmonica player Marion Wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isomorphism (crystallography)
In chemistry isomorphism has meanings both at the level of crystallography and at a molecular level. In crystallography, compounds are isomorphous if their symmetry is the same and their unit cell parameters are similar Molecules are isomorphous if they have similar shapes. The coordination complexes tris(acetylacetonato)iron (Fe(acac)3) and tris(acetylacetonato)aluminium (Al(acac)3) are isomorphous. These compounds, both of ''D''3 symmetry have very similar shapes, as determined by bond lengths and bond angles. Isomorphous compounds give rise to isomorphous crystals and form solid solutions. Historically, crystal shape was defined by measuring the angles between crystal faces with a goniometer. Whereas crystals of Fe(acac)3 are deep red and crystals of Al(acac)3 are colorless, a solid solution of the two, i.e. Fe1−xAlx(acac)3 will be deep or pale pink depending on the Fe/Al ratio, x. Double sulfates, such as Tutton's salt, with the generic formula MI2MII(SO4)2.6H2O, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnesium Sulfide
Magnesium sulfide is an inorganic compound with the formula Mg S. It is a white crystalline material but often is encountered in an impure form that is brown and non-crystalline powder. It is generated industrially in the production of metallic iron. Preparation and general properties MgS is formed by the reaction of sulfur or hydrogen sulfide with magnesium. It crystallizes in the rock salt structure as its most stable phase, its zinc blende and wurtzite structures can be prepared by molecular beam epitaxy. The chemical properties of MgS resemble those of related ionic sulfides such as those of sodium, barium, or calcium. It reacts with oxygen to form the corresponding sulfate, magnesium sulfate. MgS reacts with water to give hydrogen sulfide and magnesium hydroxide. Applications In the BOS steelmaking process, sulfur is the first element to be removed. Sulfur is removed from the impure blast furnace iron by the addition of several hundred kilograms of magnesium powder by a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selenide
A selenide is a chemical compound containing a selenium anion with oxidation number of −2 (Se2−), much as sulfur does in a sulfide. The chemistry of the selenides and sulfides is similar. Similar to sulfide, in aqueous solution, the selenide ion, Se2−, is prevalent only in very basic conditions. In neutral conditions, hydrogen selenide ion, HSe−, is most common. In acid conditions, hydrogen selenide, H2Se, is formed. Some selenides are reactive to oxidation by air. Owing to the greater reducing power of selenide, metal selenides are more easily decomposed to the elements than are sulfides (tellurides are even more labile). Selenides of electropositive metals: such as aluminium selenide readily hydrolyse, even in moist air, evolving toxic hydrogen selenide gas. Pure selenide minerals are rare, instead selenium tends to partially substitute for sulfide in many sulfide minerals. The degree of substitution is only of commercial interest for copper sulfide ores, in which case ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telluride (chemistry)
The telluride ion is the anion Te2− and its derivatives. It is analogous to the other chalcogenide anions, the lighter O2−, S2−, and Se2−, and the heavier Po2−. In principle, Te2− is formed by the two-e− reduction of tellurium. The redox potential is −1.14 V. :Te(s) + 2 e− ↔ Te2− Although solutions of the telluride dianion have not been reported, soluble salts of bitelluride (TeH−) are known. Organic tellurides ''Tellurides'' also describe a class of organotellurium compounds formally derived from Te2−. An illustrative member is dimethyl telluride, which results from the methylation of telluride salts: :2 CH3I + Na2Te → (CH3)2Te + 2 NaI Dimethyl telluride is formed by the body when tellurium is ingested. Such compounds are often called telluroethers because they are structurally related to ethers with tellurium replacing oxygen, although the length of the C–Te bond is much longer than a C–O bond. C–Te–C angles tend to be close ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
