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Selenite Fluorides
A selenite fluoride is a chemical compound or salt that contains fluoride and Selenite (ion), selenite anions ( and ). These are mixed anion compounds. Some have third anions, including nitrate (), molybdate (), oxalate (), selenate (), silicate () and tellurate (). Naming A selenite fluoride compound may also be called a fluoride oxoselenate(IV) using IUPAC naming for inorganic compounds. Production Rare-earth element, Rare earth selenite fluorides can be produced by dissolving the rare earth selenate into molten lithium fluoride at over 800°C, whereupon the selenate loses oxygen to become selenite, and crystals of the selenite fluoride can form. Another similar method involves heating the rare earth oxide, with a rare earth fluoride and selenium dioxide with a caesium bromide flux. If glass or silica containers are used, they are eaten away by the molten flux and silicates are formed some of which may be fluoride selenite silicate compounds. Related Related to these are t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluoride
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 nom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caesium Bromide
Caesium bromide or cesium bromide is an ionic compound of caesium and bromine with the chemical formula CsBr. It is a white or transparent solid with melting point at 636 °C that readily dissolves in water. Its bulk crystals have the cubic CsCl structure, but the structure changes to the rocksalt type in nanometer-thin film grown on mica, LiF, KBr or NaCl substrates. Synthesis Caesium bromide can be prepared via following reactions: * Neutralization: : CsOH (aq) + HBr (aq) → CsBr (aq) + H2O (l) : Cs2(CO3) (aq) + 2 HBr (aq) → 2 CsBr (aq) + H2O (l) + CO2 (g) * Direct synthesis: : 2 Cs (s) + Br2 (g) → 2 CsBr (s) The direct synthesis is a vigorous reaction of caesium with other halogens. Due to its high cost, it is not used for preparation. Uses Caesium bromide is sometimes used in optics as a beamsplitter component in wide-band spectrophotometers Spectrophotometry is a branch of electromagnetic spectroscopy concerned with the quantitative measurement of the ref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selenites
Selenite may refer to: Substances containing selenium *A selenium-containing anion or ionic compound with the SeO32− anion: **Selenite (ion), anion is a selenium oxoanion with the chemical formula SeO32− ***Selenous acid, the conjugate acid, with the formula H2SeO3 ***Salts of this anion: **** Silver selenite, an inorganic compound of formula Ag2SeO3 ****Sodium selenite, a salt, a colourless solid, and the most common water-soluble selenium compound *Selenite broth, an enrichment medium for the isolation of ''Salmonella'' species Other * Selenite (mineral), a variety of gypsum (CaSO4·2H2O) * ''Selenites'' is a synonym of ''Zophos'', a genus of land snails in the family Haplotrematidae * Selenite Range, a mountain range in Pershing County, Nevada ** Selenite Peak, a summit in the Selenite Range, Nevada * Selenite, a high class citizen that experienced space travel, from the videogame ''Event_0'' * Selenite, a fictional native inhabitant of the Moon; see Moon in science ficti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Second Harmonic Generator
The second (symbol: s) is the unit of time in the International System of Units (SI), historically defined as of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds each (24 × 60 × 60 = 86400). The current and formal definition in the International System of Units ( SI) is more precise:The second ..is defined by taking the fixed numerical value of the caesium frequency, Δ''ν''Cs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be when expressed in the unit Hz, which is equal to s−1. This current definition was adopted in 1967 when it became feasible to define the second based on fundamental properties of nature with caesium clocks. Because the speed of Earth's rotation varies and is slowing ever so slightly, a leap second is added at irregular intervals to civil time to keep clocks in sync with Earth's rotation. Uses Analog clocks and watches often ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Group
In mathematics, physics and chemistry, a space group is the symmetry group of an object in space, usually in three dimensions. The elements of a space group (its symmetry operations) are the rigid transformations of an object that leave it unchanged. In three dimensions, space groups are classified into 219 distinct types, or 230 types if chiral copies are considered distinct. Space groups are discrete cocompact groups of isometries of an oriented Euclidean space in any number of dimensions. In dimensions other than 3, they are sometimes called Bieberbach groups. In crystallography, space groups are also called the crystallographic or Fedorov groups, and represent a description of the symmetry of the crystal. A definitive source regarding 3-dimensional space groups is the ''International Tables for Crystallography'' . History Space groups in 2 dimensions are the 17 wallpaper groups which have been known for several centuries, though the proof that the list was complete was only ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Weight
A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and biochemistry, the distinction from ions is dropped and ''molecule'' is often used when referring to polyatomic ions. A molecule may be homonuclear, that is, it consists of atoms of one chemical element, e.g. two atoms in the oxygen molecule (O2); or it may be heteronuclear, a chemical compound composed of more than one element, e.g. water (two hydrogen atoms and one oxygen atom; H2O). In the kinetic theory of gases, the term ''molecule'' is often used for any gaseous particle regardless of its composition. This relaxes the requirement that a molecule contains two or more atoms, since the noble gases are individual atoms. Atoms and complexes connected by non-covalent interactions, such as hydrogen bonds or ionic bonds, are typically not consi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tellurite Fluoride
A tellurite fluoride is a mixed anion compound containing tellurite and fluoride ions. They have also been called oxyfluorotellurate(IV) where IV is the oxidation state In chemistry, the oxidation state, or oxidation number, is the hypothetical charge of an atom if all of its bonds to different atoms were fully ionic. It describes the degree of oxidation (loss of electrons) of an atom in a chemical compound. C ... of tellurium in tellurite. Comparable compounds are sulfite fluorides or selenite fluorides. List References {{Fluorides Fluorides Tellurites Mixed anion compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfite Fluoride
Sulfites or sulphites are compounds that contain the sulfite ion (or the sulfate(IV) ion, from its correct systematic name), . The sulfite ion is the conjugate base of bisulfite. Although its acid (sulfurous acid) is elusive, its salts are widely used. Sulfites are substances that naturally occur in some foods and the human body. They are also used as regulated food additives. When in food or drink, sulfites are often lumped together with sulfur dioxide.SeREGULATION (EU) No 1169/2011 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL/ref> Structure The structure of the sulfite anion can be described with three equivalent resonance structures. In each resonance structure, the sulfur atom is double-bonded to one oxygen atom with a formal charge of zero (neutral), and sulfur is singly bonded to the other two oxygen atoms, which each carry a formal charge of −1, together accounting for the −2 charge on the anion. There is also a non-bonded lone pair on the sulfur, so the structure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chalcogen
The chalcogens (ore forming) ( ) are the chemical elements in group 16 of the periodic table. This group is also known as the oxygen family. Group 16 consists of the elements oxygen (O), sulfur (S), selenium (Se), tellurium (Te), and the radioactive elements polonium (Po) and livermorium (Lv). Often, oxygen is treated separately from the other chalcogens, sometimes even excluded from the scope of the term "chalcogen" altogether, due to its very different chemical behavior from sulfur, selenium, tellurium, and polonium. The word "chalcogen" is derived from a combination of the Greek word () principally meaning copper (the term was also used for bronze/brass, any metal in the poetic sense, ore or coin), and the Latinized Greek word , meaning ''born'' or ''produced''. Sulfur has been known since antiquity, and oxygen was recognized as an element in the 18th century. Selenium, tellurium and polonium were discovered in the 19th century, and livermorium in 2000. All of the chalcogens h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selenite Bromide
Selenite may refer to: Substances containing selenium *A selenium-containing anion or ionic compound with the SeO32− anion: **Selenite (ion), anion is a selenium oxoanion with the chemical formula SeO32− ***Selenous acid, the conjugate acid, with the formula H2SeO3 ***Salts of this anion: ****Silver selenite, an inorganic compound of formula Ag2SeO3 **** Sodium selenite, a salt, a colourless solid, and the most common water-soluble selenium compound *Selenite broth, an enrichment medium for the isolation of ''Salmonella'' species Other *Selenite (mineral), a variety of gypsum (CaSO4·2H2O) * ''Selenites'' is a synonym of '' Zophos'', a genus of land snails in the family Haplotrematidae * Selenite Range, a mountain range in Pershing County, Nevada ** Selenite Peak Selenite Peak is a summit located in Pershing County, Nevada, United States. Description Selenite Peak is the fifth-highest peak of the Selenite Range which is a subset of the Great Basin Ranges. This peak is s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selenite Chloride
Selenite may refer to: Substances containing selenium *A selenium-containing anion or ionic compound with the SeO32− anion: **Selenite (ion), anion is a selenium oxoanion with the chemical formula SeO32− ***Selenous acid, the conjugate acid, with the formula H2SeO3 ***Salts of this anion: ****Silver selenite, an inorganic compound of formula Ag2SeO3 **** Sodium selenite, a salt, a colourless solid, and the most common water-soluble selenium compound *Selenite broth, an enrichment medium for the isolation of ''Salmonella'' species Other *Selenite (mineral), a variety of gypsum (CaSO4·2H2O) * ''Selenites'' is a synonym of '' Zophos'', a genus of land snails in the family Haplotrematidae * Selenite Range, a mountain range in Pershing County, Nevada ** Selenite Peak Selenite Peak is a summit located in Pershing County, Nevada, United States. Description Selenite Peak is the fifth-highest peak of the Selenite Range which is a subset of the Great Basin Ranges. This peak is s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithium Fluoride
Lithium fluoride is an inorganic compound with the chemical formula LiF. It is a colorless solid, that transitions to white with decreasing crystal size. Although odorless, lithium fluoride has a bitter-saline taste. Its structure is analogous to that of sodium chloride, but it is much less soluble in water. It is mainly used as a component of molten salts. Formation of LiF from the elements releases one of the highest energy per mass of reactants, second only to that of BeO. Manufacturing LiF is prepared from lithium hydroxide or lithium carbonate with hydrogen fluoride. Applications Precursor to LiPF6 for batteries Lithium fluoride is reacted with hydrogen fluoride (HF) and phosphorus pentachloride to make lithium hexafluorophosphate, an ingredient in lithium ion battery electrolyte. In molten salts Fluorine is produced by the electrolysis of molten potassium bifluoride. This electrolysis proceeds more efficiently when the electrolyte contains a few percent of LiF, possibly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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