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Sesquioxidizing
A sesquioxide is an oxide of an Chemical element, element (or Radical (chemistry), radical), where the ratio between the number of atoms of that element and the number of atoms of oxygen is 2:3. For example, aluminium oxide and phosphorus(III) oxide are sesquioxides. Many sesquioxides contain a metal in the +3 oxidation state and the oxide ion , e.g., aluminium oxide , lanthanum(III) oxide and iron(III) oxide . Sesquioxides of iron and aluminium are found in soil. The alkali metal sesquioxides are exceptions because they contain both peroxide and superoxide ions, e.g., rubidium sesquioxide is formulated . Sesquioxides of metalloids and nonmetals are exceptions too, e.g. boron trioxide , dinitrogen trioxide and phosphorus(III) oxide . Many transition metal oxides crystallize in the corundum structure type, with space group Rc. Sesquioxides of rare earth elements crystalize into one or more of three crystal structures: hexagonal (type A, space group Pm1), monoclinic (type B, sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scrabble
''Scrabble'' is a word game in which two to four players score points by placing tiles, each bearing a single letter, onto a game board divided into a 15×15 grid of squares. The tiles must form words that, in crossword fashion, read left to right in rows or downward in columns and are included in a standard dictionary or lexicon. The name ''Scrabble'' is a trademark of Mattel in most of the world, except in the United States and Canada, where it is a trademark of Hasbro, under the brands of both of its subsidiaries, Milton Bradley and Parker Brothers. The game is sold in 121 countries and is available in more than 30 languages; approximately 150 million sets have been sold worldwide, and roughly one-third of American and half of British homes have a ''Scrabble'' set. There are approximately 4,000 ''Scrabble'' clubs around the world. Game details The game is played by two to four players on a square game board imprinted with a 15×15 grid of cells (individually known as " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxide
An oxide () is a chemical compound that contains at least one oxygen atom and one other element in its chemical formula. "Oxide" itself is the dianion of oxygen, an O2– (molecular) ion. with oxygen in the oxidation state of −2. Most of the Earth's crust consists of oxides. Even materials considered pure elements often develop an oxide coating. For example, aluminium foil develops a thin skin of Al2O3 (called a passivation layer) that protects the foil from further corrosion.Greenwood, N. N.; & Earnshaw, A. (1997). Chemistry of the Elements (2nd Edn.), Oxford:Butterworth-Heinemann. . Stoichiometry (the measurable relationship between reactants and chemical equations of a equation or reaction) Oxides are extraordinarily diverse in terms of stoichiometries and in terms of the structures of each stoichiometry. Most elements form oxides of more than one stoichiometry. A well known example is carbon monoxide and carbon dioxide.Greenwood, N. N.; & Earnshaw, A. (1997). Chemistry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rubidium Sesquioxide
Rubidium sesquioxide is a chemical compound with the formula or . In terms of oxidation states, Rubidium in this compound has a nominal charge of +1, and the oxygen is a mixed peroxide () and superoxide () for a structural formula of . It has been studied theoretically as an example of a strongly correlated material. The compound was predicted to be a rare example of a ferromagnetic compound that is magnetic due to a p-block element, and a half-metal that was conducting in the minority spin band. However, while the material does have exotic magnetic behavior, experimental results instead showed an electrically insulating magnetically frustrated system. also displays a Verwey transition where charge ordering appears at 290 K. Rubidium sesquioxide can be prepared by reacting the peroxide and the superoxide : : It is initially discovered in 1907, and more thoroughly characterized in 1939. The compound crystallizes in a body-centered cubic form with the same crystal structure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
B2O3
Boron trioxide or diboron trioxide is the oxide of boron with the formula . It is a colorless transparent solid, almost always glassy (amorphous), which can be crystallized only with great difficulty. It is also called boric oxide or boria. It has many important industrial applications, chiefly in ceramics as a flux for glazes and enamels and in the production of glasses. Structure Boron trioxide has three known forms, one amorphous and two crystalline. Amorphous form The amorphous form (g-) is by far the most common. It is thought to be composed of boroxol rings which are six-membered rings composed of alternating 3-coordinate boron and 2-coordinate oxygen. Because of the difficulty of building disordered models at the correct density with many boroxol rings, this view was initially controversial, but such models have recently been constructed and exhibit properties in excellent agreement with experiment. It is now recognized, from experimental and theoretical studies, that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SOWPODS
Collins Scrabble Words (CSW, formerly SOWPODS) is the word list used in English-language tournament Scrabble in most countries except the US, Thailand and Canada. The term SOWPODS is an anagram of the two abbreviations '' OSPD'' (Official Scrabble Players Dictionary) and '' OSW'' (Official Scrabble Words), these being the original two official dictionaries used in various parts of the world at the time. Although the two source dictionaries have now changed their respective titles, the term SOWPODS is still used by tournament players to refer to the combination of the two sources. There has not been any actual hard-copy list produced called SOWPODS, although the current Collins Scrabble Words, or CSW, is in effect the full SOWPODS list by a different name. Currently the two main sources for the words making up the combined list (generally known as Collins) are: * The British words. Derived from two sources; the ''Collins English Dictionary'' and the ''Collins Corpus'', and * The Ame ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxford English Dictionary
The ''Oxford English Dictionary'' (''OED'') is the first and foundational historical dictionary of the English language, published by Oxford University Press (OUP). It traces the historical development of the English language, providing a comprehensive resource to scholars and academic researchers, as well as describing usage in its many variations throughout the world. Work began on the dictionary in 1857, but it was only in 1884 that it began to be published in unbound fascicles as work continued on the project, under the name of ''A New English Dictionary on Historical Principles; Founded Mainly on the Materials Collected by The Philological Society''. In 1895, the title ''The Oxford English Dictionary'' was first used unofficially on the covers of the series, and in 1928 the full dictionary was republished in 10 bound volumes. In 1933, the title ''The Oxford English Dictionary'' fully replaced the former name in all occurrences in its reprinting as 12 volumes with a one-v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gyles Brandreth
Gyles Daubeney Brandreth (born 8 March 1948) is an English broadcaster, writer and former politician. He has worked as a television presenter, theatre producer, journalist, author and publisher. He was a presenter for TV-am's '' Good Morning Britain'' in the 1980s, and has been regularly featured on Channel 4's game show ''Countdown'' and the BBC's ''The One Show''. On radio, he makes frequent appearances on the BBC Radio 4 programme '' Just a Minute''. In 1992, Brandreth was elected to the House of Commons as the Conservative Member of Parliament (MP) for the City of Chester constituency. He served until he was defeated in 1997, and resumed his career in the media. He has written both fiction and non-fiction books, and makes appearances as a public speaker. Early life Brandreth was born on 8 March 1948 in Wuppertal, West Germany, where his father, Charles Brandreth, was serving as a legal officer with the Allied Control Commission. He moved to London with his parents at th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rare Earth Elements
The rare-earth elements (REE), also called the rare-earth metals or (in context) rare-earth oxides or sometimes the lanthanides (yttrium and scandium are usually included as rare earths), are a set of 17 nearly-indistinguishable lustrous silvery-white soft heavy metals. Compounds containing rare earths have diverse applications in electrical and electronic components, lasers, glass, magnetic materials, and industrial processes. Scandium and yttrium are considered rare-earth elements because they tend to occur in the same ore deposits as the lanthanides and exhibit similar chemical properties, but have different electronic and magnetic properties. These metals tarnish slowly in air at room temperature and react slowly with cold water to form hydroxides, liberating hydrogen. They react with steam to form oxides, and at elevated temperature (400°C) ignite spontaneously. These elements and their compounds have no biological function other than in several specialized enzymes, su ... [...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] |
Corundum
Corundum is a crystalline form of aluminium oxide () typically containing traces of iron, titanium, vanadium and chromium. It is a rock-forming mineral. It is a naturally transparent material, but can have different colors depending on the presence of transition metal impurities in its crystalline structure. Corundum has two primary gem varieties: ruby and sapphire. Rubies are red due to the presence of chromium, and sapphires exhibit a range of colors depending on what transition metal is present. A rare type of sapphire, padparadscha sapphire, is pink-orange. The name "corundum" is derived from the Tamil- Dravidian word ''kurundam'' (ruby-sapphire) (appearing in Sanskrit as ''kuruvinda''). Because of corundum's hardness (pure corundum is defined to have 9.0 on the Mohs scale), it can scratch almost all other minerals. It is commonly used as an abrasive on sandpaper and on large tools used in machining metals, plastics, and wood. Emery, a variety of corundum with no value a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transition Metal
In chemistry, a transition metal (or transition element) is a chemical element in the d-block of the periodic table (groups 3 to 12), though the elements of group 12 (and less often group 3) are sometimes excluded. They are the elements that can use d orbitals as valence orbitals to form chemical bonds. The lanthanide and actinide elements (the f-block) are called inner transition metals and are sometimes considered to be transition metals as well. Since they are metals, they are lustrous and have good electrical and thermal conductivity. Most (with the exception of group 11 and group 12) are hard and strong, and have high melting and boiling temperatures. They form compounds in any of two or more different oxidation states and bind to a variety of ligands to form coordination complexes that are often coloured. They form many useful alloys and are often employed as catalysts in elemental form or in compounds such as coordination complexes and oxides. Most are strongly param ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinitrogen Trioxide
Dinitrogen trioxide is the chemical compound with the formula N2O3. It is one of the simple nitrogen oxides. It forms upon mixing equal parts of nitric oxide and nitrogen dioxide and cooling the mixture below −21 °C (−6 °F): :NO + NO2 N2O3 Dinitrogen trioxide is only isolable at low temperatures, i.e. in the liquid and solid phases. In liquid and solid states, it has a deep blue color. At higher temperatures the equilibrium favors the constituent gases, with ''K''diss = 193 kPa (25 °C). This compound is sometimes called "nitrogen trioxide", but this name properly refers to another compound, the (uncharged) nitrate radical . Structure and bonding Typically, N–N bonds are similar in length to that in hydrazine (145 pm). Dinitrogen trioxide, however, has an unusually long N–N bond at 186 pm. Some other nitrogen oxides also possess long N–N bonds, including dinitrogen tetroxide (175 pm). The N2O3 molecule is planar and exhibits Cs symmet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
