query: what is the atomic number of molybdenum?

title: Molybdenum

text: Low levels of prolonged exposure can cause irritation to the eyes and skin. Direct inhalation or ingestion of molybdenum and its oxides should be avoided. OSHA regulations specify the maximum permissible molybdenum exposure in an 8-hour day as 5 mg/m. Chronic exposure to 60 to 600 mg/m can cause symptoms including fatigue, headaches and joint pains. At levels of 5000 mg/m, molybdenum is immediately dangerous to life and health. Molybdenum Molybdenum is a chemical element with symbol Mo and atomic number 42. The name is from Neo-Latin "molybdaenum", from Ancient Greek ", meaning lead, since its ores were confused with

title: Molybdenum

text: Molybdenum Molybdenum is a chemical element with symbol Mo and atomic number 42. The name is from Neo-Latin "molybdaenum", from Ancient Greek ", meaning lead, since its ores were confused with lead ores. Molybdenum minerals have been known throughout history, but the element was discovered (in the sense of differentiating it as a new entity from the mineral salts of other metals) in 1778 by Carl Wilhelm Scheele. The metal was first isolated in 1781 by Peter Jacob Hjelm. Molybdenum does not occur naturally as a free metal on Earth; it is found only in various oxidation states in minerals.

title: Isotopes of molybdenum

text: Isotopes of molybdenum Molybdenum (Mo) has 33 known isotopes, ranging in atomic mass from 83 to 115, as well as four metastable nuclear isomers. Seven isotopes occur naturally, with atomic masses of 92, 94, 95, 96, 97, 98, and 100. Of these naturally occurring isotopes, six (all but Mo) have never been observed to decay, but Mo and Mo are theoretically capable of radioactive decay. All unstable isotopes of molybdenum decay into isotopes of zirconium, niobium, technetium, and ruthenium. Molybdenum-100 is the only naturally occurring isotope that is not stable. Molybdenum-100 has a half-life of approximately 1×10 y and undergoes

title: Molybdenum

text: oxygen or water at room temperature. Weak oxidation of molybdenum starts at ; bulk oxidation occurs at temperatures above 600 °C, resulting in molybdenum trioxide. Like many heavier transition metals, molybdenum shows little inclination to form a cation in aqueous solution, although the Mo cation is known under carefully controlled conditions. There are 35 known isotopes of molybdenum, ranging in atomic mass from 83 to 117, as well as four metastable nuclear isomers. Seven isotopes occur naturally, with atomic masses of 92, 94, 95, 96, 97, 98, and 100. Of these naturally occurring isotopes, only molybdenum-100 is unstable. Molybdenum-98 is

title: Isotopes of molybdenum

text: double beta decay into ruthenium-100. Molybdenum-98 is the most common isotope, comprising 24.14% of all molybdenum on Earth. Molybdenum isotopes with mass numbers 111 and up all have half-lives of approximately .15 s. Molybdenum-99 is produced commercially by intense neutron-bombardment of a highly purified uranium-235 target, followed rapidly by extraction. It is used as a parent radioisotope in technetium-99m generators to produce the even shorter-lived daughter isotope technetium-99m, which is used in many medical procedures. Isotopes of molybdenum Molybdenum (Mo) has 33 known isotopes, ranging in atomic mass from 83 to 115, as well as four metastable nuclear isomers. Seven

title: Atomic number

text: Atomic number The atomic number or proton number (symbol "Z") of a chemical element is the number of protons found in the nucleus of an atom. It is identical to the charge number of the nucleus. The atomic number uniquely identifies a chemical element. In an uncharged atom, the atomic number is also equal to the number of electrons. The sum of the atomic number "Z" and the number of neutrons, "N", gives the mass number "A" of an atom. Since protons and neutrons have approximately the same mass (and the mass of the electrons is negligible for many purposes)

title: Atomic number

text: atomic numbers 1 to 118 have been observed. Synthesis of new elements is accomplished by bombarding target atoms of heavy elements with ions, such that the sum of the atomic numbers of the target and ion elements equals the atomic number of the element being created. In general, the half-life becomes shorter as atomic number increases, though an "island of stability" may exist for undiscovered isotopes with certain numbers of protons and neutrons. Atomic number The atomic number or proton number (symbol "Z") of a chemical element is the number of protons found in the nucleus of an atom. It

title: Molybdenum ditelluride

text: refractive index, and greater absorbance. Cadmium telluride solar cells are often deposited on a backplate of molybdenum. Molybdenum ditelluride can form at the contact, and if this is n-type it will degrade the performance of the solar cell. Small pieces of nanolayers of molybdenum ditelluride can be mixed in and dispersed in molten pewter without reacting, and it causes a doubling of the stiffness of the resultant composite. Molybdenum ditelluride has been used as a substrate for examining proteins with an atomic force microscope. It is superior because the protein sticks harder than with more traditional materials such as mica.

title: Atomic number

text: neutral atom, which is "Z" (the atomic number). The configuration of these electrons follows from the principles of quantum mechanics. The number of electrons in each element's electron shells, particularly the outermost valence shell, is the primary factor in determining its chemical bonding behavior. Hence, it is the atomic number alone that determines the chemical properties of an element; and it is for this reason that an element can be defined as consisting of "any" mixture of atoms with a given atomic number. The quest for new elements is usually described using atomic numbers. As of 2010, all elements with

title: Molybdenum ditelluride

text: examined with scanning tunneling microscopy can show either a pattern of tellurium atoms or a pattern of molybdenum atoms on different parts. When the scanning tip is further from the surface only tellurium atoms are visible. This is explained by the d orbitals from molybdenum penetrating up through the surface layer of tellurium. The molybdenum can supply a much bigger current than tellurium. But at greater distance only the p orbital from tellurium can be detected. Lower voltages than used for α form still produce atomic images. Friction force microscopy (FFM) has been used to get a slip-stick image at

title: Atomic number

text: and the mass defect of nucleon binding is always small compared to the nucleon mass, the atomic mass of any atom, when expressed in unified atomic mass units (making a quantity called the "relative isotopic mass"), is within 1% of the whole number "A". Atoms with the same atomic number "Z" but different neutron numbers "N", and hence different atomic masses, are known as isotopes. A little more than three-quarters of naturally occurring elements exist as a mixture of isotopes (see monoisotopic elements), and the average isotopic mass of an isotopic mixture for an element (called the relative atomic mass)

title: Effective atomic number

text: interactions. For instance, lithium, atomic number 3, has two electrons in the 1s shell and one in the 2s shell. Because the two 1s electrons screen the protons to give an effective atomic number for the 2s electron close to 1, we can treat this 2s valence electron with a hydrogenic model. Mathematically, the effective atomic number Z can be calculated using methods known as "self-consistent field" calculations, but in simplified situations is just taken as the atomic number minus the number of electrons between the nucleus and the electron being considered. An alternative definition of the effective atomic number

title: Molybdenum

text: a silvery-grey metal with a Mohs hardness of 5.5, and a standard atomic weight of 95.95 g/mol. It has a melting point of ; of the naturally occurring elements, only tantalum, osmium, rhenium, tungsten, and carbon have higher melting points. It has one of the lowest coefficients of thermal expansion among commercially used metals. The tensile strength of molybdenum wires increases about 3 times, from about 10 to 30 GPa, when their diameter decreases from ~50–100 nm to 10 nm. Molybdenum is a transition metal with an electronegativity of 2.16 on the Pauling scale. It does not visibly react with

title: Effective atomic number

text: Effective atomic number Effective atomic number has two different meanings: one that is the effective nuclear charge of an atom, and one that calculates the average atomic number for a compound or mixture of materials. Both are abbreviated Z. The effective atomic number Z, (sometimes referred to as the effective nuclear charge) of an atom is the number of protons that an electron in the element effectively 'sees' due to screening by inner-shell electrons. It is a measure of the electrostatic interaction between the negatively charged electrons and positively charged protons in the atom. One can view the electrons in

title: Effective atomic number

text: is one quite different from that described above. The atomic number of a material exhibits a strong and fundamental relationship with the nature of radiation interactions within that medium. There are numerous mathematical descriptions of different interaction processes that are dependent on the atomic number, Z. When dealing with composite media (i.e. a bulk material composed of more than one element), one therefore encounters the difficulty of defining Z. An effective atomic number in this context is equivalent to the atomic number but is used for compounds (e.g. water) and mixtures of different materials (such as tissue and bone). This

title: Molybdenum hexafluoride

text: a number of elements including molybdenum at moderately elevated temperature. Molybdenum hexafluoride Molybdenum hexafluoride, also molybdenum(VI) fluoride is the inorganic compound with the formula MoF. It is the highest fluoride of molybdenum. A colourless solid, it melts just below room temperature. It is one of the seventeen known binary hexafluorides. Molybdenum hexafluoride is made by direct reaction of molybdenum metal in an excess of elemental fluorine: Typical impurities are MoOF and MoOF, reflecting the tendency of the hexafluoride to hydrolyze. At −140 °C, it crystallizes in the orthorhombic space group "Pnma". Lattice parameters are "a" = 9.394 Å, "b" =

title: Atomic number

text: in a defined environment on Earth, determines the element's standard atomic weight. Historically, it was these atomic weights of elements (in comparison to hydrogen) that were the quantities measurable by chemists in the 19th century. The conventional symbol "Z" comes from the German word meaning "number", which, before the modern synthesis of ideas from chemistry and physics, merely denoted an element's numerical place in the periodic table, whose order is approximately, but not completely, consistent with the order of the elements by atomic weights. Only after 1915, with the suggestion and evidence that this "Z" number was also the nuclear

title: Molybdenum

text: the Moon. The comparative rarity of molybdenum in the Earth's crust is offset by its concentration in a number of water-insoluble ores, often combined with sulfur in the same way as copper, with which it is often found. Though molybdenum is found in such minerals as wulfenite (PbMoO) and powellite (CaMoO), the main commercial source is molybdenite (MoS). Molybdenum is mined as a principal ore and is also recovered as a byproduct of copper and tungsten mining. The world's production of molybdenum was 250,000 tonnes in 2011, the largest producers being China (94,000 t), the United States (64,000 t), Chile

title: Atomic number

text: charge and a physical characteristic of atoms, did the word (and its English equivalent "atomic number") come into common use in this context. Loosely speaking, the existence or construction of a periodic table of elements creates an ordering of the elements, and so they can be numbered in order. Dmitri Mendeleev claimed that he arranged his first periodic tables (first published on March 6th, 1869) in order of atomic weight ("Atomgewicht"). However, in consideration of the elements' observed chemical properties, he changed the order slightly and placed tellurium (atomic weight 127.6) ahead of iodine (atomic weight 126.9). This placement is

title: Effective atomic number

text: possible to obtain a much more accurate single-valued Z by weighting against the spectrum of the source. The effective atomic number for electron interactions may be calculated with a similar approach; see for instance Taylor "et al." 2009 and Taylor 2011. The cross-section based approach for determining Z is obviously much more complicated than the simple power-law approach described above, and this is why freely-available software has been developed for such calculations (Taylor "et al." 2012). Effective atomic number Effective atomic number has two different meanings: one that is the effective nuclear charge of an atom, and one that calculates

title: Atomic number

text: was seen as containing 118 neutrons rather than 118 nuclear electrons, and its positive charge now was realized to come entirely from a content of 79 protons. After 1932, therefore, an element's atomic number "Z" was also realized to be identical to the proton number of its nuclei. The conventional symbol "Z" possibly comes from the German word (atomic number). However, prior to 1915, the word "Zahl" (simply "number") was used for an element's assigned number in the periodic table. Each element has a specific set of chemical properties as a consequence of the number of electrons present in the

title: Molybdenum mining in the United States

text: leading molybdenum producer in 2013, with 13,600 metric tons of molybdenum. The mine is owned by Climax Molybdenum Company The Thompson Creek mine, in Custer County, Idaho, is owned by the Thompson Creek Metals Co., Inc. The mine was a large producer in 2014, but was put on inactive status in December 2014. As of 2014, there were ten US copper mines producing molybdenum as a byproduct. The number of mines producing byproduct molybdenum at any given time depends on the price of molybdenum and the amount of molybdenite in the ore. Both copper sulfides and molydenite are separated from

title: Molybdenum mining in the United States

text: the gangue by froth flotation. To separate the molybdenite from the copper sulfides, the copper/molybdenum concentrate is run through a molybdenite recovery flotation circuit, in which chemicals are added to "depress" the copper, meaning to prevent the copper sulfide minerals from attaching to the froth, while the molybdenum is unaffected. A few plants do the opposite, adding other chemicals to depress the molybdenum while the copper floats. There are a number of undeveloped and currently inactive molybdenum deposits in the United States. Inactive mines Deposits not yet mined The United States dominated molybdenum production for most of the 20th century,

title: Effective atomic number

text: comparing materials. In many textbooks and scientific publications, the following - simplistic and often dubious - sort of method is employed. One such proposed formula for the effective atomic number, Z, is as follows (Murty 1965): An example is that of water (HO), made up of two hydrogen atoms (Z=1) and one oxygen atom (Z=8), the total number of electrons is 1+1+8 = 10, so the fraction of electrons for the two hydrogens is (2/10) and for the one oxygen is (8/10). So the Z for water is: The effective atomic number is important for predicting how photons interact with

title: Atomic number

text: consistent with the modern practice of ordering the elements by proton number, "Z", but that number was not known or suspected at the time. A simple numbering based on periodic table position was never entirely satisfactory, however. Besides the case of iodine and tellurium, later several other pairs of elements (such as argon and potassium, cobalt and nickel) were known to have nearly identical or reversed atomic weights, thus requiring their placement in the periodic table to be determined by their chemical properties. However the gradual identification of more and more chemically similar lanthanide elements, whose atomic number was not

title: Atomic number

text: obvious, led to inconsistency and uncertainty in the periodic numbering of elements at least from lutetium (element 71) onward (hafnium was not known at this time). In 1911, Ernest Rutherford gave a model of the atom in which a central core held most of the atom's mass and a positive charge which, in units of the electron's charge, was to be approximately equal to half of the atom's atomic weight, expressed in numbers of hydrogen atoms. This central charge would thus be approximately half the atomic weight (though it was almost 25% different from the atomic number of gold ,

title: Atomic number

text: tube. The square root of the frequency of these photons increased from one target to the next in an arithmetic progression. This led to the conclusion (Moseley's law) that the atomic number does closely correspond (with an offset of one unit for K-lines, in Moseley's work) to the calculated electric charge of the nucleus, i.e. the element number "Z". Among other things, Moseley demonstrated that the lanthanide series (from lanthanum to lutetium inclusive) must have 15 members—no fewer and no more—which was far from obvious from the chemistry at that time. After Moseley's death in 1915, the atomic numbers of

title: Molybdenum

text: and [MoO]. Polymolybdates can incorporate other ions, forming polyoxometalates. The dark-blue phosphorus-containing heteropolymolybdate P[MoO] is used for the spectroscopic detection of phosphorus. The broad range of oxidation states of molybdenum is reflected in various molybdenum chlorides: Molybdenum(VI) chloride MoCl is not known, although the molybdenum hexafluoride is well characterized. Like chromium and some other transition metals, molybdenum forms quadruple bonds, such as in Mo(CHCOO) and [MoCl], which also has a quadruple bond. The oxidation state 0 is possible with carbon monoxide as ligand, such as in molybdenum hexacarbonyl, Mo(CO). Molybdenite—the principal ore from which molybdenum is now extracted—was previously known

title: Molybdenum

text: tungstate is a competitive inhibitor of molybdenum. Dietary tungsten reduces the concentration of molybdenum in tissues. Low soil concentration of molybdenum in a geographical band from northern China to Iran results in a general dietary molybdenum deficiency, and is associated with increased rates of esophageal cancer. Compared to the United States, which has a greater supply of molybdenum in the soil, people living in those areas have about 16 times greater risk for esophageal squamous cell carcinoma. Molybdenum deficiency has also been reported as a consequence of non-molybdenum supplemented total parenteral nutrition (complete intravenous feeding) for long periods of time.

title: Molybdenum

text: It results in high blood levels of sulfite and urate, in much the same way as molybdenum cofactor deficiency. However (presumably since pure molybdenum deficiency from this cause occurs primarily in adults), the neurological consequences are not as marked as in cases of congenital cofactor deficiency. A congenital molybdenum cofactor deficiency disease, seen in infants, is an inability to synthesize molybdenum cofactor, the heterocyclic molecule discussed above that binds molybdenum at the active site in all known human enzymes that use molybdenum. The resulting deficiency results in high levels of sulfite and urate, and neurological damage. High levels of molybdenum

title: Molybdenum

text: the most abundant isotope, comprising 24.14% of all molybdenum. Molybdenum-100 has a half-life of about 10 y and undergoes double beta decay into ruthenium-100. Molybdenum isotopes with mass numbers from 111 to 117 all have half-lives of approximately 150 ns. All unstable isotopes of molybdenum decay into isotopes of niobium, technetium, and ruthenium. As also noted below, the most common isotopic molybdenum application involves molybdenum-99, which is a fission product. It is a parent radioisotope to the short-lived gamma-emitting daughter radioisotope technetium-99m, a nuclear isomer used in various imaging applications in medicine. In 2008, the Delft University of Technology applied

title: Molybdenum

text: for a patent on the molybdenum-98-based production of molybdenum-99. Molybdenum forms chemical compounds in oxidation states from -II to +VI. Higher oxidation states are more relevant to its terrestrial occurrence and its biological roles, mid-level oxidation states are often associated with metal clusters, and very low oxidation states are typically associated with organomolybdenum compounds. Mo and W chemistry shows strong similarities. The relative rarity of molybdenum(III), for example, contrasts with the pervasiveness of the chromium(III) compounds. The highest oxidation state is seen in molybdenum(VI) oxide (MoO), whereas the normal sulfur compound is molybdenum disulfide MoS. From the perspective of commerce,

title: Molybdenum

text: usually extracted with aqueous ammonia to give ammonium molybdate: Copper, an impurity in molybdenite, is less soluble in ammonia. To completely remove it from the solution, it is precipitated with hydrogen sulfide. Ammonium molybdate converts to ammonium dimolybdate, which is isolated as a solid. Heating this solid gives molybdenum trioxide: Crude trioxide can be further purified by sublimation at . Metallic molybdenum is produced by reduction of the oxide with hydrogen: The molybdenum for steel production is reduced by the aluminothermic reaction with addition of iron to produce ferromolybdenum. A common form of ferromolybdenum contains 60% molybdenum. Molybdenum had a

title: Molybdenum mining in the United States

text: for 47% of US molybdenum production in 2013. In both molybdenum porphyries and copper porphyries, the molybdenum is present as molybdenite. The Climax mine, historically the world’s largest source of molybdenum, is north of Leadville, Colorado. Climax first produced molybdenum in 1915, and was worked continuously from 1924 until it was shut down in 1995. Formerly an underground mine, the Climax mine reopened as a surface mine in 2012. It is owned by the Climax Molybdenum Company and now operates as an open pit. The Henderson molybdenum mine, near Empire, Colorado, started producing molybdenum in 1976, and was the nation’s

title: Molybdenum

text: aircraft parts, electrical contacts, industrial motors, and filaments. Most high-strength steel alloys (for example, 41xx steels) contain 0.25% to 8% molybdenum. Even in these small portions, more than 43,000 tonnes of molybdenum are used each year in stainless steels, tool steels, cast irons, and high-temperature superalloys. Molybdenum is also valued in steel alloys for its high corrosion resistance and weldability. Molybdenum contributes corrosion resistance to type-300 stainless steels (specifically type-316) and especially so in the so-called superaustenitic stainless steels (such as alloy AL-6XN, 254SMO and 1925hMo). Molybdenum increases lattice strain, thus increasing the energy required to dissolve iron atoms from

title: Molybdenum blue

text: involves "digesting" molybdenum sulfide with nitric acid to form molybdic acid, which is then mixed with tin filings and a little muriatic acid (HCl). This is evaporated and heated with alumina. A 1955 paper states that molybdenum blue is unstable and is not used commercially as a pigment. The chemistry of these pigments has not been investigated. Molybdenum blue Molybdenum blue is a term applied to: The "heteropoly-molybdenum blues", are used extensively in analytical chemistry and as catalysts. The formation of "isopoly-molybdenum blues" which are intense blue has been used as a sensitive test for reducing reagents. They have recently

title: Molybdenum mining in the United States

text: Molybdenum mining in the United States Molybdenum mining in the United States produced 65,500 metric tons of molybdenum in 2014, worth US$1.8 billion. The US was the world’s second-largest molybdenum producer, after China, and provided 25% of the world’s supply of molybdenum. The US was a major exporter of molybdenum; net exports made up 48% of US production. Because most molybdenum is used as a steel alloy, demand for, and therefore the price of, molybdenum, tracks the demand for steel. As of the end of 2014, the United States had 2.7 million tons of molybdenum reserves, and 5.4 million tons

title: Molybdenum hexafluoride

text: Molybdenum hexafluoride Molybdenum hexafluoride, also molybdenum(VI) fluoride is the inorganic compound with the formula MoF. It is the highest fluoride of molybdenum. A colourless solid, it melts just below room temperature. It is one of the seventeen known binary hexafluorides. Molybdenum hexafluoride is made by direct reaction of molybdenum metal in an excess of elemental fluorine: Typical impurities are MoOF and MoOF, reflecting the tendency of the hexafluoride to hydrolyze. At −140 °C, it crystallizes in the orthorhombic space group "Pnma". Lattice parameters are "a" = 9.394 Å, "b" = 8.543 Å, and "c" = 4.959 Å. There are four

title: Molybdenum

text: the surface. Molybdenum is also used to enhance the corrosion resistance of ferritic (for example grade 444) and martensitic (for example 1.4122 and 1.4418) stainless steels. Because of its lower density and more stable price, molybdenum is sometimes used in place of tungsten. An example is the 'M' series of high-speed steels such as M2, M4 and M42 as substitution for the 'T' steel series, which contain tungsten. Molybdenum can also be used as a flame-resistant coating for other metals. Although its melting point is , molybdenum rapidly oxidizes at temperatures above making it better-suited for use in vacuum environments.

title: Atomic number

text: ), the single element from which Rutherford made his guess). Nevertheless, in spite of Rutherford's estimation that gold had a central charge of about 100 (but was element on the periodic table), a month after Rutherford's paper appeared, Antonius van den Broek first formally suggested that the central charge and number of electrons in an atom was "exactly" equal to its place in the periodic table (also known as element number, atomic number, and symbolized "Z"). This proved eventually to be the case. The experimental position improved dramatically after research by Henry Moseley in 1913. Moseley, after discussions with Bohr

title: Molybdenum ditelluride

text: Molybdenum ditelluride Molybdenum(IV) telluride, molybdenum ditelluride or just molybdenum telluride is a compound of molybdenum and tellurium with formula MoTe, corresponding to a mass percentage of 27.32% molybdenum and 72.68% tellurium. It can crystallise in two dimensional sheets which can be thinned down to monolayers that are flexible and almost transparent. It is a semiconductor, and can fluoresce. It is part of a class of materials called transition metal dichalcogenides. As a semiconductor the band gap lies in the infrared region. This raises the potential use as a semiconductor in electronics or an infrared detector. MoTe can be prepared by

title: Molybdenum

text: the most important compounds are molybdenum disulfide () and molybdenum trioxide (). The black disulfide is the main mineral. It is roasted in air to give the trioxide: The trioxide, which is volatile at high temperatures, is the precursor to virtually all other Mo compounds as well as alloys. Molybdenum has several oxidation states, the most stable being +4 and +6 (bolded in the table at left). Molybdenum(VI) oxide is soluble in strong alkaline water, forming molybdates (MoO). Molybdates are weaker oxidants than chromates. They tend to form structurally complex oxyanions by condensation at lower pH values, such as [MoO]

title: Molybdenum

text: in the process of regulating nitrogen, sulfur, and carbon. In some animals, and in humans, the oxidation of xanthine to uric acid, a process of purine catabolism, is catalyzed by xanthine oxidase, a molybdenum-containing enzyme. The activity of xanthine oxidase is directly proportional to the amount of molybdenum in the body. However, an extremely high concentration of molybdenum reverses the trend and can act as an inhibitor in both purine catabolism and other processes. Molybdenum concentration also affects protein synthesis, metabolism, and growth. Mo is as a component in most nitrogenases. Among molybdoenzymes, nitrogenases are unique in lacking the molybdopterin.

title: Molybdenum

text: Nitrogenases catalyze the production of ammonia from atmospheric nitrogen: The biosynthesis of the FeMoco active site is highly complex. Molybdate is transported in the body as MoO. Molybdenum is an essential trace dietary element. Four mammalian Mo-dependent enzymes are known, all of them harboring a pterin-based molybdenum cofactor (Moco) in their active site: sulfite oxidase, xanthine oxidoreductase, aldehyde oxidase, and mitochondrial amidoxime reductase. People severely deficient in molybdenum have poorly functioning sulfite oxidase and are prone to toxic reactions to sulfites in foods. The human body contains about 0.07 mg of molybdenum per kilogram of body weight, with higher concentrations

title: Molybdenum ditelluride

text: β–MoTe is a comparatively good hydrogen evolution electrocatalyst showing even in unsupported form and without any additional nanostructuring a Tafel slope of 78 mV/dec. The semiconducting polymorph of α–MoTe was found inactive for HER. The superior activity was attributed to higher conductivity of β–MoTe phase. Molybdenum ditelluride Molybdenum(IV) telluride, molybdenum ditelluride or just molybdenum telluride is a compound of molybdenum and tellurium with formula MoTe, corresponding to a mass percentage of 27.32% molybdenum and 72.68% tellurium. It can crystallise in two dimensional sheets which can be thinned down to monolayers that are flexible and almost transparent. It is a semiconductor,

title: Molybdenum trioxide

text: have one short molybdenum-oxygen bond to a non-bridging oxygen. MoO is produced industrially by roasting molybdenum disulfide, the chief ore of molybdenum: The laboratory synthesis of the dihydrate entails acidification of aqueous solutions of sodium molybdate with perchloric acid: The dihydrate loses water readily to give the monohydrate. Both are bright yellow in color. Molybdenum trioxide dissolves slightly in water to give "molybdic acid". In base, it dissolves to afford the molybdate anion. Molybdenum trioxide is used to manufacture molybdenum metal, which serves as an additive to steel and corrosion-resistant alloys. The relevant conversion entails treatment of MoO with hydrogen

title: Molybdenum

text: The free element, a silvery metal with a gray cast, has the sixth-highest melting point of any element. It readily forms hard, stable carbides in alloys, and for this reason most of world production of the element (about 80%) is used in steel alloys, including high-strength alloys and superalloys. Most molybdenum compounds have low solubility in water, but when molybdenum-bearing minerals contact oxygen and water, the resulting molybdate ion is quite soluble. Industrially, molybdenum compounds (about 14% of world production of the element) are used in high-pressure and high-temperature applications as pigments and catalysts. In its pure form, molybdenum is

title: Molybdenum mining in the United States

text: of identified molybdenum resource. Molybdenum is produced in the US from porphyry deposits of two types. The first class, which produces molybdenum as the primary product, includes molybdenum porphyry deposits. In 2014, three such molybdenum porphyry deposits were mined: two in Colorado and one in Idaho; the mine in Idaho was put into inactive status at the end of 2014. The second class, which produces molybdenum as a byproduct of copper mining, includes copper porphyry deposits. In 2014, byproduct molybdenum was produced at ten porphyry copper mines, in Arizona, Montana, Nevada, and New Mexico. Byproduct molybdenum from copper mines accounted

title: Molybdenum

text: (70%/30%) are used for piping, stirrers and pump impellers that come into contact with molten zinc. Molybdenum is an essential element in most organisms. In fact a scarcity of molybdenum in the Earth's early oceans may have strongly influenced evolution of eukaryotic life (which includes all plants and animals). At least 50 molybdenum-containing enzymes have been identified, mostly in bacteria. those enzymes include aldehyde oxidase, sulfite oxidase and xanthine oxidase. With one exception, Mo in proteins is bound by molybdopterin to give the molybdenum cofactor. In terms of function, molybdoenzymes catalyze the oxidation and sometimes reduction of certain small molecules

title: Molybdenum

text: Columbia yield molybdenite as their primary product, while many porphyry copper deposits such as the Bingham Canyon Mine in Utah and the Chuquicamata mine in northern Chile produce molybdenum as a byproduct of copper mining. About 86% of molybdenum produced is used in metallurgy, with the rest used in chemical applications. The estimated global use is structural steel 35%, stainless steel 25%, chemicals 14%, tool & high-speed steels 9%, cast iron 6%, molybdenum elemental metal 6%, and superalloys 5%. Molybdenum can withstand extreme temperatures without significantly expanding or softening, making it useful in environments of intense heat, including military armor,

title: Molybdenum

text: TZM (Mo (~99%), Ti (~0.5%), Zr (~0.08%) and some C) is a corrosion-resisting molybdenum superalloy that resists molten fluoride salts at temperatures above . It has about twice the strength of pure Mo, and is more ductile and more weldable, yet in tests it resisted corrosion of a standard eutectic salt (FLiBe) and salt vapors used in molten salt reactors for 1100 hours with so little corrosion that it was difficult to measure. Other molybdenum-based alloys that do not contain iron have only limited applications. For example, because of its resistance to molten zinc, both pure molybdenum and molybdenum-tungsten alloys

title: Molybdenum deficiency (plant disorder)

text: plants. The size and number of root nodules are often reduced. Molybdenum deficiency is common in many different types of soil; some soils have low total Mo concentrations, and others have low plant-available Mo due to strong Mo sorption. Symptoms are most common where both conditions apply, such as in acid sandy soils. Molybdenum may be strongly sorbed in ironstone soils. Liming of soils frequently relieves Mo deficiency by decreasing Mo sorption. Molybdenum is an essential micronutrient which means it is essential for plant growth and development, but is required in very small quantities. Although Mo requirements vary among crops,

title: Molybdenum disulfide

text: Molybdenum disulfide Molybdenum disulfide is an inorganic compound composed of molybdenum and sulfur. Its chemical formula is . The compound is classified as a transition metal dichalcogenide. It is a silvery black solid that occurs as the mineral molybdenite, the principal ore for molybdenum. is relatively unreactive. It is unaffected by dilute acids and oxygen. In appearance and feel, molybdenum disulfide is similar to graphite. It is widely used as a dry lubricant because of its low friction and robustness. Bulk is a diamagnetic, indirect bandgap semiconductor similar to silicon, with a bandgap of 1.23 eV. MoS is naturally found

title: Henderson molybdenum mine

text: Henderson molybdenum mine The Henderson molybdenum mine is a large underground molybdenum mine west of the town of Empire in Clear Creek County, Colorado, USA. The Henderson mine, which has produced molybdenum since 1976, is owned by Freeport-McMoRan. The Henderson mine is North America's largest producer of primary molybdenum. 2007 production was 40 million pounds of molybdenum, with a value of $1.1 billion. The Henderson mine is near the Urad mine, which produced molybdenum from 1914 to the 1960s, before exhausting its orebody. The owner, Climax Molybdenum Co., recognized the potential for deeper orebodies in the area, and discovered the

title: Molybdenum(III) chloride

text: Molybdenum(III) chloride Molybdenum(III) chloride is the inorganic compound with the formula MoCl. The chemical formula of molybdenum trichloride is MoCl3. Molybdenum trichloride is synthesized by the reduction of molybdenum pentachloride with hydrogen. The greatest yield is instead produced by the reduction of pure molybdenum (V) chloride, using anhydrous tin (II) chloride as a reducing agent. This procedure must be performed under a moisture-free and oxygen-free atmosphere of prepurified nitrogen. There are two structures of molybdenum trichloride- alpha (α) and beta (β). The alpha structure is similar to that of aluminum chloride (AlCl3). In this structure, molybdenum has octahedral coordination geometry

title: Molybdenum disulfide

text: 229 GPa, which matches the experimental results within error. Bertolazzi and coworkers also characterized the failure modes of the suspended monolayer flakes. The strain at failure ranges from 6 to 11%. The average yield strength of monolayer MoS is 23 GPa, which is close to the theoretical fracture strength for defect-free MoS. The band structure of MoS is sensitive to strain. Molybdenum disulfide is stable in air and attacked only by aggressive reagents. It reacts with oxygen upon heating forming molybdenum trioxide: Chlorine attacks molybdenum disulfide at elevated temperatures to form molybdenum pentachloride: Molybdenum disulfide is a host for formation

title: Molybdenum trioxide

text: Molybdenum trioxide Molybdenum trioxide is chemical compound with the formula MoO. This compound is produced on the largest scale of any molybdenum compound. It occurs as the rare mineral molybdite. Its chief application is as an oxidation catalyst and as a raw material for the production of molybdenum metal. In the gas phase, three oxygen atoms are double bonded to the central molybdenum atom. In the solid state, anhydrous MoO is composed of layers of distorted MoO octahedra in an orthorhombic crystal. The octahedra share edges and form chains which are cross-linked by oxygen atoms to form layers. The octahedra

title: Molybdenum hexacarbonyl

text: allyl chloride gives [MoCl(allyl)(CO)(MeCN)], whereas treatment with KTp and sodium cyclopentadienide gives [MoTp(CO)] and [MoCp(CO)] anions, respectively. These anions react with a variety of electrophiles. A related source of Mo(CO) is cycloheptatrienemolybdenum tricarbonyl. Molybdenum hexacarbonyl is widely used in electron beam-induced deposition technique - it is easily vaporized and decomposed by the electron beam providing a convenient source of molybdenum atoms. Like all metal carbonyls, Mo(CO) is dangerous source of volatile metal as well as CO. It diffuses readily into plastic stoppers. Molybdenum hexacarbonyl Molybdenum hexacarbonyl (also called molybdenum carbonyl) is the chemical compound with the formula Mo(CO). This colorless

title: Effective atomic number

text: the other side; each electron will feel less than the attractive force of 26 protons because the other electron contributes a repelling force. The 4s electrons in Iron, which are furthest from the nucleus, feel an effective atomic number of only 5.43 because of the 25 electrons in between it and the nucleus screening the charge. Effective atomic numbers are useful not only in understanding why electrons further from the nucleus are so much more weakly bound than those closer to the nucleus, but also because they can tell us when to use simplified methods of calculating other properties and

title: Molybdenum ditelluride

text: decreases to 236.6 cm for single layer. The A mode lowers its frequency as the number of layers decreases, becoming 172.4 cm for the monolayer. MoTe commonly exists in three crystalline forms with rather similar layered structures: hexagonal α, monoclinic β and orthorhombic β'. At room temperature it crystallises in the hexagonal system similar to molybdenum disulfide. Crystals are platy or flat. MoTe has unit cell sizes of a=3.519 Å c=13.964 Å and a specific gravity of 7.78 g·cm. Each molybdenum atom is surrounded by six tellurium atoms in a trigonal prism with the separation of these Mo and Te

title: Effective atomic number

text: electrons further away are screened from the nucleus by other electrons in between, and feel less electrostatic interaction as a result. The 1s electron of Iron (the closest one to the nucleus) sees an effective atomic number (number of protons) of 25. The reason why it is not 26 is because some of the electrons in the atom end up repelling the others, giving a net lower electrostatic interaction with the nucleus. One way of envisioning this effect is to imagine the 1s electron sitting on one side of the 26 protons in the nucleus, with another electron sitting on

title: Effective atomic number

text: for the photoelectric process which incorporates a ‘constant’ of 2.64 x 10, which is in fact not a constant but rather a function of the photon energy. A linear relationship between Z has been shown for a limited number of compounds for low-energy x-rays, but within the same publication it is shown that many compounds do not lie on the same trendline (Spiers "et al." 1946). As such, for polyenergetic photon sources (in particular, for applications such as radiotherapy), the effective atomic number varies significantly with energy (Taylor "et al." 2008). As shown by Taylor "et al." (2008), it is

title: Molybdenum blue

text: Molybdenum blue Molybdenum blue is a term applied to: The "heteropoly-molybdenum blues", are used extensively in analytical chemistry and as catalysts. The formation of "isopoly-molybdenum blues" which are intense blue has been used as a sensitive test for reducing reagents. They have recently been shown to contain very large anionic species based on the so-called "big wheel" containing 154 Mo atoms, with a formula [MoOH(HO)]. The molybdenum blue pigment is historically documented but may not be in use today. The first heteropoly molybdate and first heteropolymetallate, yellow ammonium phosphomolybdate, (NH)PMoO was discovered by Berzelius in 1826. The phosphorus atom in

title: Molybdenum ditelluride

text: at 618.46 xu. Atomic force microscopy (AFM) of the van der Waals surface of α-MoTe shows alternating rows of smooth balls, which are the tellurium atoms. AFM images are often done on a silica (SiO) surface on silicon. A monolayer of α-MoTe has its surface 0.9 nm above the silica, and each extra layer of α-MoTe adds 0.7 nm. Scanning tunneling microscopy (STM) of α-MoTe reveals a hexagonal grid like chicken wire, where the molybdenum atoms are contributing to the current. Higher bias voltages are required to get an image, either over 0.5 V or below −0.3 V. β-MoTe surfaces

title: Molybdenum(V) chloride

text: Molybdenum(V) chloride Molybdenum(V) chloride is the inorganic compound with the formula [MoCl]. This dark volatile solid is used in research to prepare other molybdenum compounds. it is moisture-sensitive and soluble in chlorinated solvents. Usually called molybdenum pentachloride, it is in fact a dimer with the formula MoCl. Each molybdenum has local octahedral symmetry and two chlorides bridge between the molybdenum centers. A similar structure is also found for the pentachlorides of W, Nb and Ta. In the gas phase and partly in solution, the dimers partially dissociates to give a monomeric pentahalide. The monomer is paramagnetic, with one unpaired electron

title: Molybdenum bronze

text: at about 160 °C. Molybdenum bronzes are classified in three major families: The hydrogen molydbdenum bronzes have similar appearances but different compositions: Other molybdenum bronzes with anomalous electrical properties have been reported, which do not fit in these families. These include Molybdenum bronze In chemistry, molybdenum bronze is a generic name for certain mixed oxides of molybdenum with the generic formula where A may be hydrogen, an alkali metal cation (such as Li, Na, K), and Tl. These compounds form deeply coloured plate-like crystals with a metallic sheen, hence their name. These bronzes derive their metallic character partially occupied 4d-bands.

title: China Molybdenum

text: China Molybdenum China Molybdenum Company Limited ( or , , ) is the largest molybdenum producer in Mainland China and top 5 in the world listed in the Hong Kong Stock Exchange and Shanghai Stock Exchange. It is one of the largest tungsten producers in the world, and is the second largest Cobalt and Niobium Producer and the leading Copper producer worldwide. The headquarters of the company is at Luanchuan County, Luoyang City, Henan Province. The chairman is Mr. Li Chaochun (). On 26 April 2007, China Molybdenum was listed in Hong Kong Stock Exchange. Its stock was closed at

title: Molybdenum mining in the United States

text: producing more than half the world's production each year from 1925 through 1981. In 1953, US mines supplied 92 percent of world molybdenum production. The US was the world’s leading molybdenum producer from 1924 through 2006, after which US production was overtaken by China. Molybdenum mining in the United States Molybdenum mining in the United States produced 65,500 metric tons of molybdenum in 2014, worth US$1.8 billion. The US was the world’s second-largest molybdenum producer, after China, and provided 25% of the world’s supply of molybdenum. The US was a major exporter of molybdenum; net exports made up 48% of

title: Molybdenum disilicide

text: signal speed. Molybdenum disilicide Molybdenum disilicide (MoSi, or molybdenum silicide), an intermetallic compound, a silicide of molybdenum, is a refractory ceramic with primary use in heating elements. It has moderate density, melting point 2030 °C, and is electrically conductive. At high temperatures it forms a passivation layer of silicon dioxide, protecting it from further oxidation. It is a gray metallic-looking material with tetragonal crystal structure (alpha-modification); its beta-modification is hexagonal and unstable. It is insoluble in most acids but soluble in nitric acid and hydrofluoric acid. While MoSi has excellent resistance to oxidation and high Young's modulus at temperatures above

title: Molybdenum disilicide

text: Molybdenum disilicide Molybdenum disilicide (MoSi, or molybdenum silicide), an intermetallic compound, a silicide of molybdenum, is a refractory ceramic with primary use in heating elements. It has moderate density, melting point 2030 °C, and is electrically conductive. At high temperatures it forms a passivation layer of silicon dioxide, protecting it from further oxidation. It is a gray metallic-looking material with tetragonal crystal structure (alpha-modification); its beta-modification is hexagonal and unstable. It is insoluble in most acids but soluble in nitric acid and hydrofluoric acid. While MoSi has excellent resistance to oxidation and high Young's modulus at temperatures above 1000 °C,

title: Molybdenum

text: U.S. Institute of Medicine (now the National Academy of Medicine, NAM) updated its Estimated Average Requirements (EARs) and Recommended Dietary Allowances (RDAs) for molybdenum. If there is not sufficient information to establish EARs and RDAs, an estimate designated Adequate Intake (AI) is used instead. An AI of 2 micrograms (μg) of molybdenum per day was established for infants up to 6 months of age, and 3 μg/day from 7 to 12 months of age, both for males and females. For older children and adults, the following daily RDAs have been established for molybdenum: 17 μg from 1 to 3 years

title: Molybdenum

text: produced by the propellant of the one ton shell. After the war, demand plummeted until metallurgical advances allowed extensive development of peacetime applications. In World War II, molybdenum again saw strategic importance as a substitute for tungsten in steel alloys. Molybdenum is the 54th most abundant element in the Earth's crust and the 25th most abundant element in its oceans, with an average of 10 parts per billion; it is the 42nd most abundant element in the Universe. The Russian Luna 24 mission discovered a molybdenum-bearing grain (1 × 0.6 µm) in a pyroxene fragment taken from Mare Crisium on

title: (Mesitylene)molybdenum tricarbonyl

text: out of plane by 0.035 Å due to steric interaction with the carbonyl groups. The arene can be displaced by the trimethylphosphite via a S2 type mechanism to give the "fac"-tricarbonyltris(trimethyl phosphite)molybdenum. The tricarbonyl(mesitylene)molybdenum complex can be used an electron donor. Tricarbonyl(mesitylene)molybdenum can act as a catalyst for the polymerisation of phenylacetylene. The Molybdenum complex is activated with an oxidant such as chloranil. The result of the charge transfer facilitates ring slippage and the mesitylene group changes from η to η this allows the phenylacetylene monomer units to bind to the metal centre. (Mesitylene)molybdenum tricarbonyl (Mesitylene)molybdenum tricarbonyl is an organomolybdenum

title: Molybdenum(II) chloride

text: structurally related to [MoCl]. The tungsten analogue is known. Ta and Nb form related clusters where halides are bridge edges of the Ta octahedron vs faces. The resulting formula is [TaCl]. Sulfido and selenido derivatives are also well studied. [ReSeCl] has the same number of valence electrons as does [MoCl]. The Mo-S clusters MoSL, analogues of the "Chevrel phases", have been prepared by the reaction of sulfide sources with MoCl in the presence of donor ligands L. Molybdenum(II) chloride Molybdenum dichloride describes chemical compounds with the empirical formula MoCl. At least two forms are known, and both have attracted much

title: China Molybdenum

text: HK$10.28, which was 60% greater than HK$6.8, the IPO price. It was one of the stocks with the greatest surplus in stock price at the first trading day in 2007. China Molybdenum joined the Hang Seng China Enterprise Index from 2007 to 2010. Among its holdings is the Tenke Fungurume Mine in the Democratic Republic of Congo. The mine holds copper, as well as cobalt for lithium-ion batteries. China Molybdenum China Molybdenum Company Limited ( or , , ) is the largest molybdenum producer in Mainland China and top 5 in the world listed in the Hong Kong Stock Exchange

title: Molybdenum(III) chloride

text: and exhibits cubic close packing in its crystalline structure. The beta structure, however, exhibits hexagonal close packing. The THF complex of molybdenum trichloride is trichlorotris(tetrahydrofuran) molybdenum (III), and its chemical formula is CHOClMo. It is synthesized by stirring MoCl(THF), THF, and coarse tin powder. It is a light orange solid that is very moisture-sensitive, so it should be stored under dry argon in a freezer and in the dark. The complex has octahedral geometry. The IR spectrum is free of intense bands in the 900–1000 cm, a characteristic of molybdenum oxo species. Molybdenum(III) chloride Molybdenum(III) chloride is the inorganic compound

title: Molybdenum(II) chloride

text: Molybdenum(II) chloride Molybdenum dichloride describes chemical compounds with the empirical formula MoCl. At least two forms are known, and both have attracted much attention from academic researchers because of the unexpected structures seen for these compounds and the fact that they give rise to hundreds of derivatives. The form discussed here is MoCl. The other molybdenum(II) chloride is potassium octachlorodimolybdate. Rather than adopting a close-packed structure typical of metal dihalides, e.g., cadmium chloride, molybdenum(II) chloride forms a structure based on clusters. Molybdenum(II), which is a rather large ion, prefers to form compounds with metal-metal bonds, i.e. metal clusters. In fact

title: Atomic number

text: of the extra protons presumed present in all heavy nuclei. A helium nucleus was presumed to be composed of four protons plus two "nuclear electrons" (electrons bound inside the nucleus) to cancel two of the charges. At the other end of the periodic table, a nucleus of gold with a mass 197 times that of hydrogen, was thought to contain 118 nuclear electrons in the nucleus to give it a residual charge of + 79, consistent with its atomic number. All consideration of nuclear electrons ended with James Chadwick's discovery of the neutron in 1932. An atom of gold now

title: (Mesitylene)molybdenum tricarbonyl

text: (Mesitylene)molybdenum tricarbonyl (Mesitylene)molybdenum tricarbonyl is an organomolybdenum compound derived from the aromatic compound mesitylene (1,3,5-trimethylbenzene) and molybdenum carbonyl. It exists as pale yellow crystals, which are soluble in organic solvents but decompose when in solution. It has been examined as a catalyst and reagent. (Mesitylene)molybdenum tricarbonyl arises from the reaction of molybdenum hexacarbonyl with hot mesitylene: It can also be synthesized, with good yields by displacement of pyridine ligands of the trispyridine complex Mo(CO)(pyridine) in the presence of Lewis acids. This reaction proceeds at lower temperatures of the compound than the direct method The mesitylene group is bonded to the

title: (Mesitylene)molybdenum tricarbonyl

text: molybdenum centre through delocalized π - electron ring. The aromaticity of the ligand is indicated by its ability to undergo Friedel-Crafts reactions, e.g. with acetyl chloride. Such reactions are slower on the tricarbonyl(mesitylene)molybdenum than benzene, which suggests that the electron density contributes to the bonding to the molybdenum. The tricarbonyl(mesitylene)molybdenum complex adopts a near C symmetry with the three carbonyl groups occupying an eclipsed arrangement relative to the three methyl groups. The mesityl group is η to the molybdenum central metal atom, which lies 0.009 Å away from the ring centre and the methyl groups on the benzene are bent

title: Molybdenum ditelluride

text: current does not increase. Above 3.5 volts current leaks through the gate, and electrolysis occurs intercalating potassium atoms in the MoTe layer. The potassium intercalated molybdenum ditelluride becomes superconducting below 2.8 K. As a lubricant molybdenum ditelluride can function well in a vacuum and at temperatures up to 500 °C with a coefficient of friction below 0.1. However molybdenum disulfide has a lower friction, and molybdenum diselenide can function at higher temperatures. Related dichalcogenides can be fabricated into fairly efficient photoelectric cells. Potentially, stacked monolayers of indium nitride and molybdenum ditelluride can result in improved properties for photovoltaics, including lower

title: Molybdenum cofactor deficiency

text: a patient known as Baby Z became the first person to be successfully treated for molybdenum cofactor deficiency type A. The patient was treated with cPMP, a precursor of the molybdenum cofactor. Baby Z will require daily injections of cyclic pyranopterin monophosphate (cPMP) for the rest of her life. Molybdenum cofactor deficiency Molybdenum cofactor deficiency is a rare human disease in which the absence of molybdenum cofactor leads to accumulation of toxic levels of sulphite and neurological damage. Usually this leads to death within months of birth, due to the lack of active sulfite oxidase. Furthermore, a mutational block in

title: Effective atomic number

text: a substance, as certain types of photon interactions depend on the atomic number. The exact formula, as well as the exponent 2.94, can depend on the energy range being used. As such, readers are reminded that this approach is of very limited applicability and may be quite misleading. This 'power law' method, while commonly employed, is of questionable appropriateness in contemporary scientific applications within the context of radiation interactions in heterogeneous media. This approach dates back to the late 1930s when photon sources were restricted to low-energy x-ray units (Mayneord 1937). The exponent of 2.94 relates to an empirical formula

title: Effective atomic number

text: is of most interest in terms of radiation interaction with composite materials. For bulk interaction properties, it can be useful to define an effective atomic number for a composite medium and, depending on the context, this may be done in different ways. Such methods include (i) a simple mass-weighted average, (ii) a power-law type method with some (very approximate) relationship to radiation interaction properties or (iii) methods involving calculation based on interaction cross sections. The latter is the most accurate approach (Taylor 2012), and the other more simplified approaches are often inaccurate even when used in a relative fashion for

title: Molybdenum ditelluride

text: atoms being 2.73 Å. This results in sublayers of molybdenum sandwiched between two sublayers of tellurium atoms, and then this three layer structure is stacked. Each layer is 6.97 Å thick. Within this layer two tellurium atoms in the same sublayer subtend an angle of 80.7°. The tellurium atoms on one sublayer are directly above those in the lower sublayer, and they subtend an angle of 83.1° at the molybdenum atom. The other Te-Mo-Te angle across sublayers is 136.0°. The distance between molybdenum atoms within a sublayer is 3.518 Å. This is the same as the distance between tellurium atoms

title: Molybdenum dioxide

text: deposited on graphite. Molybdenum oxide has also been suggested as possible anode material for Li-ion batteries. The mineralogical form of this compound is called tugarinovite, and is only very rarely found. Molybdenum dioxide Molybdenum dioxide is the chemical compound with the formula MoO. It is a violet-colored solid and is a metallic conductor. It crystallizes in a monoclinic cell, and has a distorted rutile, (TiO) crystal structure. In TiO the oxide anions are close packed and titanium atoms occupy half of the octahedral interstices (holes). In MoO the octahedra are distorted, the Mo atoms are off-centre, leading to alternating short

title: Molybdenum(V) chloride

text: to 20 °C, Br is produced and the formal oxidation state of molybdenum changes from +5 to +4. The net transformation is shown in the equation: MoBr reacts with THF to give the Mo(III) species mer-MoBr(THF). MoCl is a good Lewis acid toward non-oxidizable ligands. It forms an adduct with chloride to form [MoCl]. In organic synthesis, the compound finds occasional use in chlorinations, deoxygenation, and oxidative coupling reactions. Molybdenum(VI) chloride is known, but it cannot be prepared by addition of chlorine to MoCl. MoCl is an aggressive oxidant and readily hydrolyzes to release HCl. Molybdenum(V) chloride Molybdenum(V) chloride is

title: Molybdenum diselenide

text: Molybdenum diselenide Molybdenum diselenide () is an inorganic compound of molybdenum and selenium. Its structure is similar to that of . Compounds of this category are known as transition metal dichalcogenides, abbreviated TMDCs. These compounds, as the name suggests, are made up of a transition metals and elements of group 16 on the periodic table of the elements. Compared to , exhibits higher electrical conductivity. Like many TMDCs, is a layered material with strong in-plane bonding and weak out-of-plane interactions. These interactions lead to exfoliation into two-dimensional layers of single unit cell thickness. The most common form of these TMDCs

title: Molybdenum diselenide

text: selenide occurs in the nature as the extremely rare mineral drysdallite. Molybdenum diselenide Molybdenum diselenide () is an inorganic compound of molybdenum and selenium. Its structure is similar to that of . Compounds of this category are known as transition metal dichalcogenides, abbreviated TMDCs. These compounds, as the name suggests, are made up of a transition metals and elements of group 16 on the periodic table of the elements. Compared to , exhibits higher electrical conductivity. Like many TMDCs, is a layered material with strong in-plane bonding and weak out-of-plane interactions. These interactions lead to exfoliation into two-dimensional layers of

title: Molybdenum dioxide

text: pm. The bond length is shorter than would be expected for a single bond. The bonding is complex and involves a delocalisation of some of the Mo electrons in a conductance band accounting for the metallic conductivity. MoO can be prepared : Single crystals are obtained by chemical transport using iodine. Iodine reversibly converts MoO into the volatile species MoOI. Molybdenum oxide is a constituent of "technical molybdenum oxide" produced during the industrial processing of MoS: MoO has been reported as catalysing the dehydrogenation of alcohols, the reformation of hydrocarbons and biodiesel. Molybdenum nano-wires have been produced by reducing MoO

title: Molybdenum(II) acetate

text: authors proposed that "Mo(OCCH) was tetrahedral. This perspective changed with Mason's characterization. Mo(OCCH) is generally used as an intermediate compound in a process to form other quadruply bonded molybdenum compounds. The acetate ligands can be replaced to give new compounds such as [MoCl] and MoCl[P(CH)]. Molybdenum(II) acetate Molybdenum(II) acetate is a coordination compound with the formula Mo(OCCH). It is a yellow, diamagnetic, air-stable solid that is slightly soluble in organic solvents. Molybdenum(II) acetate is an iconic example of a compound with a metal-metal quadruple bond. It adopts the same Chinese lantern structure as related acetate dimers such as rhodium(II) acetate,

title: Molybdenum disulfide

text: as either molybdenite, a crystalline mineral, or jordisite, a rare low temperature form of molybdenite. Molybdenite ore is processed by flotation to give relatively pure . The main contaminant is carbon. also arises by thermal treatment of virtually all molybdenum compounds with hydrogen sulfide or elemental sulfur and can be produced by metathesis reactions from molybdenum pentachloride. All forms of have a layered structure, in which a plane of molybdenum atoms is sandwiched by planes of sulfide ions. These three strata form a monolayer of MoS. Bulk MoS consists of stacked monolayers, which are held together by weak van der

title: Molybdenum(III) bromide

text: the high temperature phase of titanium(III) iodide, the Ti---Ti separation is invariant. Molybdenum(III) bromide Molybdenum(III) bromide is the inorganic compound with the formula MoBr. It is a black solid that is insoluble in most solvents but dissolves in donor solvents such as pyridine. Molybdenum(III) bromide is produced by the reaction of elemental molybdenum and bromine at . It has a structure consisting of infinite chains of face-sharing octahedra with alternatingly short and long Mo-Mo contacts. The same structure is adopted by the tribromides of ruthenium and technetium.<ref name="DOI10.1016/0022-4596(72)90156-9">Dietrich Babel: "Die Verfeinerung der MoBr-Struktur (Refinement of the MoBr-Structure)" In: "Journal of

title: Effective atomic number

text: an atom as being 'stacked' by energy outside the nucleus; the lowest energy electrons (such as the 1s and 2s electrons) occupy the space closest to the nucleus, and electrons of higher energy are located further from the nucleus. The binding energy of an electron, or the energy needed to remove the electron from the atom, is a function of the electrostatic interaction between the negatively charged electrons and the positively charged nucleus. In Iron, atomic number 26, for instance, the nucleus contains 26 protons. The electrons that are closest to the nucleus will 'see' nearly all of them. However,

title: Molybdenum(III) bromide

text: Molybdenum(III) bromide Molybdenum(III) bromide is the inorganic compound with the formula MoBr. It is a black solid that is insoluble in most solvents but dissolves in donor solvents such as pyridine. Molybdenum(III) bromide is produced by the reaction of elemental molybdenum and bromine at . It has a structure consisting of infinite chains of face-sharing octahedra with alternatingly short and long Mo-Mo contacts. The same structure is adopted by the tribromides of ruthenium and technetium.<ref name="DOI10.1016/0022-4596(72)90156-9">Dietrich Babel: "Die Verfeinerung der MoBr-Struktur (Refinement of the MoBr-Structure)" In: "Journal of Solid State Chemistry." 1972, volume 4, S. 410–416, .</ref> In contrast, in

title: Molybdenum cofactor deficiency

text: Molybdenum cofactor deficiency Molybdenum cofactor deficiency is a rare human disease in which the absence of molybdenum cofactor leads to accumulation of toxic levels of sulphite and neurological damage. Usually this leads to death within months of birth, due to the lack of active sulfite oxidase. Furthermore, a mutational block in molybdenum cofactor biosynthesis causes absence of enzyme activity of xanthine dehydrogenase/oxidase and aldehyde oxidase. When caused by a mutation in the MOCS1 gene it is the type A variant. It can also be caused by a mutation in the MOCS2 gene or the GEPH gene. As of 2010, there

title: Molybdenum trioxide

text: at elevated temperatures: It is also a component of the co-catalyst used in the industrial production of acrylonitrile by the oxidation of propene and ammonia. Because of its layered structure and the ease of the Mo(VI)/Mo(V) coupling, MoO is of interest in electrochemical devices and displays. Molybdenum trioxide has also been suggested as a potential anti-microbial agent, e.g., in polymers. In contact with water, it forms H ions that can kill bacteria effectively. However, the issue of keeping the catalyst clean in an environment that would exploit such antimicrobial properties has not been explored. Molybdenum trioxide Molybdenum trioxide is chemical

title: Lithium molybdenum purple bronze

text: Lithium molybdenum purple bronze Lithium molybdenum purple bronze is a chemical compound with formula , that is, a mixed oxide of molybdenum and lithium. It can be obtained as flat crystals with a purple-red color and metallic sheen (hence the "purple bronze" name). This compound is one of several molybdenum bronzes with general formula where A is an alkali metal or thallium Tl. It stands out among them (and also among the sub-class of "purple" molybdenum bronzes) for its peculiar electrical properties, including a marked anisotropy that makes it a "quasi-1D" conductor, and a metal-to-insulator transition as it is cooled

title: Molybdenum

text: value of approximately $30,000 per tonne as of August 2009. It maintained a price at or near $10,000 per tonne from 1997 through 2003, and reached a peak of $103,000 per tonne in June 2005. In 2008, the London Metal Exchange announced that molybdenum would be traded as a commodity. Historically, the Knaben mine in southern Norway, opened in 1885, was the first dedicated molybdenum mine. It was closed in 1973 but was reopened in 2007. and now produces of molybdenum disulfide per year. Large mines in Colorado (such as the Henderson mine and the Climax mine) and in British

title: Molybdenum ditelluride

text: heating the correct ratio of the elements together at 1100 °C in a vacuum. Another method is via vapour deposition, where molybdenum and tellurium are volatilised in bromine gas and then deposited. Using bromine results in forming an n-type semiconductor, whereas using tellurium only results in a p-type semiconductor. The amount of tellurium in molybdenum ditelluride can vary, with tellurium being slightly deficient unless it is added in excess during production. Tellurium molecular proportion range from 1.97 to 2. Excess tellurium deposited during this process can be dissolved off with sulfuric acid. By annealing molybdenum film in a tellurium vapour