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Strontium Oxide
Strontium oxide or strontia, SrO, is formed when strontium reacts with oxygen. Burning strontium in air results in a mixture of strontium oxide and strontium nitride. It also forms from the decomposition of strontium carbonate SrCO3. It is a strongly basic oxide. Uses About 8% by weight of cathode ray tubes is strontium oxide, which has been the major use of strontium since 1970. Color televisions and other devices containing color cathode ray tubes sold in the United States are required by law to use strontium in the faceplate to block X-ray emission (these X-ray emitting TVs are no longer in production). Lead(II) oxide can be used in the neck and funnel, but causes discoloration when used in the faceplate. Reactions Elemental strontium is formed when strontium oxide is heated with aluminium Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other comm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cubic Crystal System
In crystallography, the cubic (or isometric) crystal system is a crystal system where the unit cell is in the shape of a cube. This is one of the most common and simplest shapes found in crystals and minerals. There are three main varieties of these crystals: *Primitive cubic (abbreviated ''cP'' and alternatively called simple cubic) *Body-centered cubic (abbreviated ''cI'' or bcc) *Face-centered cubic (abbreviated ''cF'' or fcc, and alternatively called ''cubic close-packed'' or ccp) Each is subdivided into other variants listed below. Although the ''unit cells'' in these crystals are conventionally taken to be cubes, the primitive unit cells often are not. Bravais lattices The three Bravais lattices in the cubic crystal system are: The primitive cubic lattice (cP) consists of one lattice point on each corner of the cube; this means each simple cubic unit cell has in total one lattice point. Each atom at a lattice point is then shared equally between eight adjacent cu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strontium Hydroxide
Strontium hydroxide, Sr(OH)2, is a caustic alkali composed of one strontium ion and two hydroxide ions. It is synthesized by combining a strontium salt with a strong base. Sr(OH)2 exists in anhydrous, monohydrate, or octahydrate form. Preparation Because Sr(OH)2 is slightly soluble in cold water, its preparation can be easily carried out by the addition of a strong base such as NaOH or KOH, drop by drop to a solution of any soluble strontium salt, most commonly Sr(NO3)2 (strontium nitrate). The Sr(OH)2 will precipitate out as a fine white powder. From here, the solution is filtered, and the Sr(OH)2 is washed with cold water and dried. Applications Strontium hydroxide is used chiefly in the refining of beet sugar and as a stabilizer in plastic. It may be used as a source of strontium ions when the chlorine from strontium chloride is undesirable. Strontium hydroxide absorbs carbon dioxide from the air to form strontium carbonate Strontium carbonate (SrCO3) is the carbonate s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strontium Compounds
Strontium is the chemical element with the symbol Sr and atomic number 38. An alkaline earth metal, strontium is a soft silver-white yellowish metallic element that is highly chemically reactive. The metal forms a dark oxide layer when it is exposed to air. Strontium has physical and chemical properties similar to those of its two vertical neighbors in the periodic table, calcium and barium. It occurs naturally mainly in the minerals celestine and strontianite, and is mostly mined from these. Both strontium and strontianite are named after Strontian, a village in Scotland near which the mineral was discovered in 1790 by Adair Crawford and William Cruickshank; it was identified as a new element the next year from its crimson-red flame test color. Strontium was first isolated as a metal in 1808 by Humphry Davy using the then newly discovered process of electrolysis. During the 19th century, strontium was mostly used in the production of sugar from sugar beets (see strontian pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminium
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has a great affinity towards oxygen, and forms a protective layer of oxide on the surface when exposed to air. Aluminium visually resembles silver, both in its color and in its great ability to reflect light. It is soft, non-magnetic and ductile. It has one stable isotope, 27Al; this isotope is very common, making aluminium the twelfth most common element in the Universe. The radioactivity of 26Al is used in radiodating. Chemically, aluminium is a post-transition metal in the boron group; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state. The aluminium cation Al3+ is small and highly charged; as such, it is polarizing, and bonds aluminium forms tend towards covalency. The strong affinity tow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lead(II) Oxide
Lead(II) oxide, also called lead monoxide, is the inorganic compound with the molecular formula Pb O. PbO occurs in two polymorphs: litharge having a tetragonal crystal structure, and massicot having an orthorhombic crystal structure. Modern applications for PbO are mostly in lead-based industrial glass and industrial ceramics, including computer components. It is an amphoteric oxide. Types Lead oxide exists in two types: * Red tetragonal (α-PbO), obtained at lower temperatures than the β-PbO * Yellow orthorhombic (β-PbO), which is obtained temperatures higher than Synthesis PbO may be prepared by heating lead metal in air at approximately . At this temperature it is also the end product of decomposition of other oxides of lead in air: :PbO2->[] Pb12O19 ->[] Pb12O17 ->[] Pb3O4 ->[] PbO Thermal decomposition of lead(II) nitrate or lead carbonate, lead(II) carbonate also results in the formation of PbO: :2 → 2 PbO + 4 + : → PbO + PbO is produced ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray
An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz ( to ) and energies in the range 145 eV to 124 keV. X-ray wavelengths are shorter than those of UV rays and typically longer than those of gamma rays. In many languages, X-radiation is referred to as Röntgen radiation, after the German scientist Wilhelm Conrad Röntgen, who discovered it on November 8, 1895. He named it ''X-radiation'' to signify an unknown type of radiation.Novelline, Robert (1997). ''Squire's Fundamentals of Radiology''. Harvard University Press. 5th edition. . Spellings of ''X-ray(s)'' in English include the variants ''x-ray(s)'', ''xray(s)'', and ''X ray(s)''. The most familiar use of X-rays is checking for fractures (broken bones), but X-rays are also used in other ways. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cathode Ray Tube
A cathode-ray tube (CRT) is a vacuum tube containing one or more electron guns, which emit electron beams that are manipulated to display images on a phosphorescent screen. The images may represent electrical waveforms ( oscilloscope), pictures ( television set, computer monitor), radar targets, or other phenomena. A CRT on a television set is commonly called a picture tube. CRTs have also been used as memory devices, in which case the screen is not intended to be visible to an observer. The term '' cathode ray'' was used to describe electron beams when they were first discovered, before it was understood that what was emitted from the cathode was a beam of electrons. In CRT television sets and computer monitors, the entire front area of the tube is scanned repeatedly and systematically in a fixed pattern called a raster. In color devices, an image is produced by controlling the intensity of each of three electron beams, one for each additive primary color (red, gre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strontium Carbonate
Strontium carbonate (SrCO3) is the carbonate salt of strontium that has the appearance of a white or grey powder. It occurs in nature as the mineral strontianite. Chemical properties Strontium carbonate is a white, odorless, tasteless powder. Being a carbonate, it is a weak base and therefore is reactive with acids. It is otherwise stable and safe to work with. It is practically insoluble in water (0.0001 g per 100 ml). The solubility is increased significantly if the water is saturated with carbon dioxide, to 0.1 g per 100 ml. Preparation Other than the natural occurrence as a mineral, strontium carbonate is prepared synthetically in one of two processes, both of which start with naturally occurring celestine, a mineral form of strontium sulfate (SrSO4). In the "black ash" process, celesite is roasted with coke at 1100–1300 °C to form strontium sulfide. The sulfate is reduced, leaving the sulfide: :SrSO4 + 2 C → SrS + 2 CO2 A mixtu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strontium Nitride
Strontium nitride, Sr3N2, is produced by burning strontium metal in air (resulting in a mixture with strontium oxide) or in nitrogen. Like other metal nitrides, it reacts with water to give strontium hydroxide and ammonia: :Sr3N2 + 6 H2O → 3 Sr(OH)2 + 2 NH3 See also * Beryllium nitride * Magnesium nitride * Calcium nitride Calcium nitride is the inorganic compound with the chemical formula Ca3 N2. It exists in various forms (isomorphs), α-calcium nitride being more commonly encountered. Structure α-Calcium nitride adopts an anti-bixbyite structure, similar to ... * Barium nitride References Nitrides Strontium compounds {{Inorganic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. Oxygen is Earth's most abundant element, and after hydrogen and helium, it is the third-most abundant element in the universe. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula . Diatomic oxygen gas currently constitutes 20.95% of the Earth's atmosphere, though this has changed considerably over long periods of time. Oxygen makes up almost half of the Earth's crust in the form of oxides.Atkins, P.; Jones, L.; Laverman, L. (2016).''Chemical Principles'', 7th edition. Freeman. Many major classes of organic molecules in living organisms contain oxygen atoms, such as proteins, nucleic acids, carbohydrates, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strontium
Strontium is the chemical element with the symbol Sr and atomic number 38. An alkaline earth metal, strontium is a soft silver-white yellowish metallic element that is highly chemically reactive. The metal forms a dark oxide layer when it is exposed to air. Strontium has physical and chemical properties similar to those of its two vertical neighbors in the periodic table, calcium and barium. It occurs naturally mainly in the minerals celestine and strontianite, and is mostly mined from these. Both strontium and strontianite are named after Strontian, a village in Scotland near which the mineral was discovered in 1790 by Adair Crawford and William Cruickshank; it was identified as a new element the next year from its crimson-red flame test color. Strontium was first isolated as a metal in 1808 by Humphry Davy using the then newly discovered process of electrolysis. During the 19th century, strontium was mostly used in the production of sugar from sugar beets (see strontian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barium Oxide
Barium oxide, also known as baria, is a white hygroscopic non-flammable compound with the formula BaO. It has a cubic structure and is used in cathode ray tubes, crown glass, and catalysts. It is harmful to human skin and if swallowed in large quantity causes irritation. Excessive quantities of barium oxide may lead to death. It is prepared by heating barium carbonate with coke, carbon black or tar or by thermal decomposition of barium nitrate. Uses Barium oxide is used as a coating for hot cathodes, for example, those in cathode ray tubes. It replaced lead(II) oxide in the production of certain kinds of glass such as optical crown glass. While lead oxide raised the refractive index, it also raised the dispersive power, which barium oxide does not alter. Barium oxide also has use as an ethoxylation catalyst in the reaction of ethylene oxide and alcohols, which takes place between 150 and 200 °C. It is also a source of pure oxygen through heat fluctuation. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
