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Actinium Tribromide
Actinium(III) bromide is a radioactive white crystalline solid that is a salt of actinium. It is prepared by reacting actinium(III) oxide with aluminium bromide Aluminium bromide is any chemical compound with the empirical formula AlBrx. Aluminium tribromide is the most common form of aluminium bromide. It is a colorless, sublimable hygroscopic solid; hence old samples tend to be hydrated, mostly as al ... at 750 °C. Reactions When treated with a mixture of gaseous ammonia and water vapor at 500°C, it turns into actinium oxybromide. References {{inorganic-stub Actinium compounds Bromides Actinide halides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexagonal Crystal Family
In crystallography, the hexagonal crystal family is one of the six crystal families, which includes two crystal systems (hexagonal and trigonal) and two lattice systems (hexagonal and rhombohedral). While commonly confused, the trigonal crystal system and the rhombohedral lattice system are not equivalent (see section crystal systems below). In particular, there are crystals that have trigonal symmetry but belong to the hexagonal lattice (such as α-quartz). The hexagonal crystal family consists of the 12 point groups such that at least one of their space groups has the hexagonal lattice as underlying lattice, and is the union of the hexagonal crystal system and the trigonal crystal system. There are 52 space groups associated with it, which are exactly those whose Bravais lattice is either hexagonal or rhombohedral. __TOC__ Lattice systems The hexagonal crystal family consists of two lattice systems: hexagonal and rhombohedral. Each lattice system consists of one Bravais ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actinium(III) Chloride
Actinium(III) chloride is a chemical compound containing the rare radioactive element actinium. This salt has the formula AcCl3. Molecular weight of the compound is 333.378 g/mol. Synthesis Actinium(III) chloride is made by reacting actinium hydroxide with carbon tetrachloride Carbon tetrachloride, also known by many other names (such as carbon tet for short and tetrachloromethane, also IUPAC nomenclature of inorganic chemistry, recognised by the IUPAC), is a chemical compound with the chemical formula CCl4. It is a n .... :4 Ac(OH)3 + 3 CCl4 → 4AcCl3 + 3CO2 + 6H2O References {{inorganic-stub Actinium compounds Chlorides Actinide halides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lanthanum(III) Bromide
Lanthanum(III) bromide (LaBr3) is an inorganic halide salt of lanthanum. When pure, it is a colorless white powder. The single crystals of LaBr3 are hexagonal crystals with melting point of 783 °C. It is highly hygroscopic and water-soluble. There are several hydrates, La3Br·x H2O, of the salt also known. It is often used as a source of lanthanum in chemical synthesis and as a scintillation material in certain applications. Lanthanum bromide scintillation detector The scintillator material cerium activated lanthanum bromide (LaBr3:Ce) was first produced in 2001. LaBr3:Ce-based radiation detectors offer improved energy resolution, fast emission and excellent temperature and linearity characteristics. Typical energy resolution at 662 keV is 3% as compared to sodium iodide detectors at 7%. The improved resolution is due to a photoelectron yield that is 160% greater than is achieved with sodium iodide. Another advantage of LaBr3:Ce is the nearly flat photo emission over a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actinium
Actinium is a chemical element; it has chemical symbol, symbol Ac and atomic number 89. It was discovered by Friedrich Oskar Giesel in 1902, who gave it the name ''emanium''; the element got its name by being wrongly identified with a substance André-Louis Debierne found in 1899 and called actinium. The actinide series, a set of 15 elements between actinium and lawrencium in the periodic table, are named for actinium. Together with polonium, radium, and radon, actinium was one of the first Primordial element, non-primordial radioactive elements to be discovered. A soft, silvery-white radioactive metal, actinium reacts rapidly with oxygen and moisture in air forming a white coating of actinium oxide that prevents further oxidation. As with most lanthanides and many actinides, actinium assumes oxidation state +3 in nearly all its chemical compounds. Actinium is found only in traces in uranium and thorium ores as the isotope 227Ac, which decays with a half-life of 21.772 years, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actinium(III) Oxide
Actinium(III) oxide is a chemical compound containing the rare radioactive element actinium. It has the molecular formula Ac2O3. It is similar to its corresponding lanthanum compound, lanthanum(III) oxide, and contains actinium in the oxidation state +3.Actinium (in Russian) Actinium oxide is not to be confused with Ac2O ( acetic anhydride
Acetic anhydride, or ethanoic anhydride, is the chemical compound with the chemical formula ...
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Aluminium Bromide
Aluminium bromide is any chemical compound with the empirical formula AlBrx. Aluminium tribromide is the most common form of aluminium bromide. It is a colorless, sublimable hygroscopic solid; hence old samples tend to be hydrated, mostly as aluminium tribromide hexahydrate (AlBr3·6H2O). Structure The dimeric form of aluminium tribromide (Al2Br6) predominates in the solid state, in solutions in noncoordinating solvents (e.g. CS2), in the melt, and in the gas phase. Only at high temperatures do these dimers break up into monomers: : Al2Br6 → 2 AlBr3 ΔH°diss = 59 kJ/mol The species aluminium monobromide forms from the reaction of HBr with Al metal at high temperature. It disproportionates near room temperature: :6/n " lBrsub>n" → Al2Br6 + 4 Al This reaction is reversed at temperatures higher than 1000 °C. Aluminium monobromide has been crystallographically characterized in the form the tetrameric adduct Al4Br4(NEt3)4 (Et = C2H5). This species is electronica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actinium Compounds
Actinium compounds are compounds containing the element actinium (Ac). Due to actinium's intense radioactivity, only a limited number of actinium compounds are known. These include: Actinium fluoride, AcF3, Actinium(III) chloride, AcCl3, Actinium(III) bromide, AcBr3, AcOF, AcOCl, AcOBr, Actinium(III) sulfide, Ac2S3, Actinium oxide, Ac2O3, Actinium(III) phosphate, AcPO4 and Actinium(III) nitrate, Ac(NO3)3. Except for AcPO4, they are all similar to the corresponding lanthanum compounds. They all contain actinium in the oxidation state +3.Actinium Great Soviet Encyclopedia (in Russian) In particular, the lattice constants of the analogous lanthanum and actinium compounds differ by only a few percent. Properties of actinium compounds Here ''a'', ''b'' and ''c'' are lattice constants, No is ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromides
A bromide ion is the negatively charged form (Br−) of the element bromine, a member of the halogens group on the periodic table. Most bromides are colorless. Bromides have many practical roles, being found in anticonvulsants, flame-retardant materials, and cell stains. Although uncommon, chronic toxicity from bromide can result in bromism, a syndrome with multiple neurological symptoms. Bromide toxicity can also cause a type of skin eruption, see potassium bromide. The bromide ion has an ionic radius of 196 pm. Natural occurrence Bromide is present in typical seawater (35 PSU) with a concentration of around 65 mg/L, which is about 0.2% of all dissolved salts. Seafood and deep sea plants generally have higher levels than land-derived foods. Bromargyrite—natural, crystalline silver bromide—is the most common bromide mineral known but is still very rare. In addition to silver, bromine is also in minerals combined with mercury and copper. Formation and re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
