74 tantalum ← Tungsten → rhenium Mo ↑ W ↓ Sg Periodic Table - Extended Periodic Table
General
Name, Symbol, Number	Tungsten, W, 74
Chemical series	transition metals
Group, Period, Block	6, 6, d
Appearance	grayish white, lustrous
Standard atomic weight	183.84 (1)  g·mol−1
Electron configuration	[Xe] 4f14 5d4 6s2
Electrons per shell	2, 8, 18, 32, 12, 2
Physical properties
Phase	solid
Density (near r.t.)	19. Tantalum (ˈtæntələm (formerly tantalium /tænˈtæliəm/ is a Chemical element with the symbol Ta and Atomic number 73 Rhenium (ˈriːniəm is a Chemical element with the symbol Re and Atomic number 75 Molybdenum (məˈlɪbdənəm from the Greek word for the metal " Lead " is a Group 6 Chemical element with the symbol Mo Seaborgium (siːˈbɔrgiəm is a Chemical element in the Periodic table that has the symbol Sg and Atomic number 106 Image of Seaborgium This is a typical display of the periodic table of the elements and contains the symbol and Atomic number of each element Wikipedia talkFeatured lists for an explanation of this and other inclusion tags below -->This is a list of Chemical elements, sorted by name Wikipedia talkFeatured lists for an explanation of this and other inclusion tags below -->This is a list of chemical elements by symbol, including the A table of Chemical elements ordered by Atomic number and color coded according to type of element In Chemistry a group, also known as a family, is a vertical column in the Periodic table of the Chemical elements There are 18 groups in In Chemistry, the term transition metal (sometimes also called a transition element) has two possible meanings It commonly refers to any element in In Chemistry a group, also known as a family, is a vertical column in the Periodic table of the Chemical elements There are 18 groups in In the Periodic table of the elements, a period is a horizontal row of the table A block of the Periodic table of elements is a set of adjacent groups The respective highest-energy electrons in each element in a block belong to the same Atomic Biological occurrences Group 6 is notable in that it contains some of the only elements in periods 5 and 6 with a known role in the biological chemistry of living organisms molybdenum A period 6 element is one of the Chemical elements in the sixth row (or period) of the periodic table of the elements, including the Lanthanides The d-block of the periodic table of the elements consists of those Periodic table groups that contain elements in which in the atomic ground state the highest-energy The atomic mass (ma is the Mass of an atom most often expressed in unified atomic mass units The atomic mass may be considered to be the total mass To help compare different orders of magnitude, the following list describes various Mass levels between 10&minus36&thinsp kg and 1053&thinspkg In Atomic physics and Quantum chemistry, electron configuration is the arrangement of Electrons in an Atom, Molecule, or other Xenon (ˈzɛnɒn or) is a Chemical element represented by the symbol Xe. The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J An electron shell may be crudely thought of as an Orbit followed by Electrons around an Atom nucleus. In the Physical sciences a phase is a Set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties A solid' object is in the States of matter characterized by resistance to Deformation and changes of Volume. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different Room temperature (also referred to as ambient temperature) is a common term to denote a certain Temperature within enclosed space at which humans are accustomed 25  g·cm−3
Liquid density at m.p.	17. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different The melting point of a solid is the temperature range at which it changes state from solid to Liquid. 6  g·cm−3
Melting point	3695 K (3422 °C, 6192 °F)
Boiling point	5828 K (5555 °C, 10031 °F)
Critical point	13892 K, {{{mpa}}} MPa
Heat of fusion	52. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic The Celsius Temperature scale was previously known as the centigrade scale. Fahrenheit is a temperature scale named after Daniel Gabriel Fahrenheit (1686–1736 a German Physicist who proposed it in 1724 The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic The Celsius Temperature scale was previously known as the centigrade scale. Fahrenheit is a temperature scale named after Daniel Gabriel Fahrenheit (1686–1736 a German Physicist who proposed it in 1724 In Physical chemistry, Thermodynamics, Chemistry and Condensed matter physics, a critical point, also called a critical state The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic The standard Enthalpy of fusion (symbol \Delta{}H_{fus} also known as the heat of fusion or specific melting heat, is the amount of 31  kJ·mol−1
Heat of vaporization	806. The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material The enthalpy of vaporization, (symbol \Delta{}_{v}H also known as the heat of vaporization or heat of evaporation, is the Energy required 7  kJ·mol−1
Specific heat capacity	(25 °C) 24. The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material Specific heat capacity, also known simply as specific heat, is the measure of the heat energy required to increase the Temperature of a unit quantity 27  J·mol−1·K−1
Vapor pressure P(Pa) 1 10 100 1 k 10 k 100 k at T(K) 3477 3773 4137 4579 5127 5823
Atomic properties
Crystal structure	cubic body centered
Oxidation states	6, 5, 4, 3, 2, 1, 0, −1 (mildly acidic oxide)
Electronegativity	2. Vapor pressure (also known as equilibrium vapor pressure or saturation vapor pressure) is the Pressure of a Vapor in equilibrium In Mineralogy and Crystallography, a crystal structure is a unique arrangement of Atoms in a Crystal. In Chemistry, the oxidation state is an indicator of the degree of Oxidation of an Atom in a Chemical compound. In Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are " Electronegativity " is the opposite of " Electropositivity," which describes an element's ability to donate electrons 36 (Pauling scale)
Ionization energies	1st: 770 kJ/mol
	2nd: 1700 kJ/mol
Atomic radius	135  pm
Atomic radius (calc. The ionization potential, ionization energy or EI of an Atom or Molecule is the Energy required to remove an Electron The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material Atomic radius, and more generally the size of an atom, is not a precisely defined Physical quantity, nor is it constant in all circumstances A picometre ( American spelling: picometer, symbol pm) is a unit of Length in the Metric system, equal to one trillionth )	193  pm
Covalent radius	146  pm
Miscellaneous
Magnetic ordering	no data
Electrical resistivity	(20 °C) 52. The covalent radius, r cov is a measure of the size of Atom which forms part of a Covalent bond. In Physics, magnetism is one of the Phenomena by which Materials exert attractive or repulsive Forces on other Materials. Electrical resistivity (also known as specific electrical resistance) is a measure of how strongly a material opposes the flow of Electric current. 8 n Ω·m
Thermal conductivity	(300 K) 173  W·m−1·K−1
Thermal expansion	(25 °C) 4. In Physics, thermal conductivity, k is the property of a material that indicates its ability to conduct Heat. When the Temperature of a substance changes the energy that is stored in the Intermolecular bonds between atoms changes 5  µm·m−1·K−1
Speed of sound (thin rod)	(r.t.) (annealed) 4290  m·s−1
Young's modulus	411  GPa
Shear modulus	161  GPa
Bulk modulus	310  GPa
Poisson ratio	0. Sound is a vibration that travels through an elastic medium as a Wave. Room temperature (also referred to as ambient temperature) is a common term to denote a certain Temperature within enclosed space at which humans are accustomed In Solid mechanics, Young's modulus (E is a measure of the Stiffness of an isotropic elastic material In Materials science, shear modulus or modulus of rigidity, denoted by G, or sometimes S or μ, is defined as the ratio of Shear Poisson's ratio ( ν) named after Simeon Poisson, is the ratio of the relative contraction strain, or transverse strain (normal to 28
Mohs hardness	7. The Mohs scale of mineral hardness characterizes the scratch resistance of various Minerals through the ability of a harder material to scratch a softer material 5
Vickers hardness	3430  MPa
Brinell hardness	2570  MPa
CAS registry number	7440-33-7
Selected isotopes
Main article: Isotopes of tungsten iso NA half-life DM DE (MeV) DP 180W 0. The Vickers hardness test was developed in 1924 by Smith and Sandland as an alternative method to measure the Hardness of materials The Brinell scale characterizes the indentation Hardness of materials through the scale of penetration of an indenter loaded on a material test-piece CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to Naturally occurring Tungsten ( W) consists of five Isotopes whose half-lives are so long that they can be considered stable. Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides In Chemistry, natural abundance (NA refers to the abundance Isotopes of a Chemical element as naturally found on a planet Half-Life (computer-game page here It's already listed in the disambiguation page Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. The decay energy is the Energy released by a Nuclear decay. The energy difference of the Reactants is often written as Q: where Q In Nuclear physics, a decay product, also known as a daughter product, daughter isotope or daughter nuclide, is a Nuclide 12% 1.8×1018 y α 2. To help compare Orders of magnitude of different times this page lists times longer than 1019 Seconds (317 billion years Alpha decay is a type of radioactive decay in which an Atomic nucleus emits an Alpha particle (two protons and two neutrons bound together into a particle 516 176Hf 181W syn 121. Hafnium (ˈhæfniəm is a Chemical element that has the symbol Hf and Atomic number 72 A synthetic radioisotope is a Radionuclide that is not found in nature no natural process or mechanism exists which produces it or it is so unstable that it decays away in 2 d ε 0. A day (symbol d is a unit of Time equivalent to 24 Hours and the duration of a single Rotation of planet Earth with respect to the Electron capture (sometimes called inverse beta decay) is a Decay mode for Isotopes that will occur when there are too many Protons in the 188 181Ta 182W 26. Tantalum (ˈtæntələm (formerly tantalium /tænˈtæliəm/ is a Chemical element with the symbol Ta and Atomic number 73 50% W is stable with 108 neutrons 183W 14. Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. 31% W is stable with 109 neutrons 184W 30. Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. 64% W is stable with 110 neutrons 185W syn 75. Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. A synthetic radioisotope is a Radionuclide that is not found in nature no natural process or mechanism exists which produces it or it is so unstable that it decays away in 1 d β- 0. A day (symbol d is a unit of Time equivalent to 24 Hours and the duration of a single Rotation of planet Earth with respect to the In Nuclear physics, beta decay is a type of Radioactive decay in which a Beta particle (an Electron or a Positron) is emitted 433 185Re 186W 28. Rhenium (ˈriːniəm is a Chemical element with the symbol Re and Atomic number 75 43% W is stable with 112 neutrons
References

Tungsten (pronounced /ˈtʌŋstən/), also known as wolfram (/ˈwʊlfrəm/), is a chemical element that has the symbol W and atomic number 74. Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. Recommended values for many properties of the elements together with various references are collected on these data pages A chemical element is a type of Atom that is distinguished by its Atomic number; that is by the number of Protons in its nucleus. See also List of elements by atomic number In Chemistry and Physics, the atomic number (also known as the proton

A steel-gray metal, tungsten is found in several ores, including wolframite and scheelite. The M acro E xpansion T emplate A ttribute L anguage complements TAL, providing macros which allow the reuse of code across An ore is a volume of rock containing components or Minerals in a mode of occurrence that renders it valuable for mining Scheelite is a Calcium Tungstate Mineral with the Chemical formula Ca[[tungsten W]] O 4 It is remarkable for its robust physical properties, especially the fact that it has the highest melting point of all the non-alloyed metals and the second highest of all the elements after carbon. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. An alloy is a Solid solution or Homogeneous mixture of two or more elements, at least one of which is a Metal, which itself has Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 ^[1] Tungsten is often brittle and hard to work in its raw state; however, if pure, it can be cut with a hacksaw. Metalworking is craft and practice of working with Metals to create individual parts assemblies or large scale structures A hacksaw is a fine-tooth saw with a Blade under Tension in a frame used for Cutting materials such as Metal or Bone ^[2] The pure form is used mainly in electrical applications, but its many compounds and alloys are used in many applications, most notably in light bulb filaments, X-ray tubes (as both the filament and target), and superalloys. The incandescent light bulb, incandescent lamp or incandescent light globe is a source of electric Light that works by Incandescence, (a general An X-ray tube is a Vacuum tube that produces X-rays They are part of X-ray machines X-rays are part of the Electromagnetic spectrum, an A superalloy, or high-performance alloy, is an Alloy that exhibits excellent mechanical strength and creep resistance at high temperatures good surface Tungsten is also the only metal from the third transition series that is known to occur in biomolecules. A biomolecule is any organic Molecule that is produced by living Organisms including large Polymeric molecules such as Proteins ^[3][4]

Contents 1 Etymology 2 Physical properties 3 Isotopes 4 Chemical properties 4.1 Compounds 4.1.1 Aqueous polyoxoanions 5 Biological role 6 Applications 7 Production 8 History 9 See also 10 References 11 External links

Etymology

"Tungsten" (from the Swedish tung sten, meaning "heavy stone") is commonly accepted as the name of the material, although some chemists (primarily in Germany but also e. Swedish ( is a North Germanic language spoken by more than nine million people predominantly in Sweden and parts of Finland, especially along the Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. g. in Sweden) refer to it as "wolfram", from its ore wolframite. "Sverige" redirects here For other uses see Sweden (disambiguation and Sverige (disambiguation. The name "wolframite" was derived from "volf rahm", the word Johan Gottschalk Wallerius used to refer to it in 1747. Johan Gottschalk Wallerius ( 11 July 1709 &ndash 16 November 1785) was a Swedish chemist and mineralogist This, in turn, was translated from "Lupi spuma", the word Georg Agricola used to refer to the element in 1546. Georgius Agricola ( March 24, 1494 – November 21, 1555) was a German scholar and scientist Its English translation is "wolf's froth", so named because the mineral consumed a large amount of tin in its extraction. Tin is a Chemical element with the symbol Sn (stannum and Atomic number 50 ^[5] Its chemical symbol, W, is derived from wolfram as well. ^[2]

Physical properties

In its raw form, tungsten is a steel-gray metal that is often brittle and hard to work. The M acro E xpansion T emplate A ttribute L anguage complements TAL, providing macros which allow the reuse of code across Metalworking is craft and practice of working with Metals to create individual parts assemblies or large scale structures However, if pure, it is much easier to work. ^[2] It is worked by forging, drawing, extruding, or sintering. Forging is the term for shaping metal by using localized compressive forces Drawing is a Manufacturing process for producing a Wire, bar or Tube by pulling on a material until it increases in length Extrusion is a process used to create objects of a fixed cross-sectional profile Sintering is a method for making objects from powder, by heating the material (below its Melting point - solid state sintering until its particles adhere Of all metals in pure form, tungsten has the highest melting point (3,422 °C, 6,192 °F), lowest vapor pressure and (at temperatures above 1,650 °C) the highest tensile strength. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. The Celsius Temperature scale was previously known as the centigrade scale. Fahrenheit is a temperature scale named after Daniel Gabriel Fahrenheit (1686–1736 a German Physicist who proposed it in 1724 Vapor pressure (also known as equilibrium vapor pressure or saturation vapor pressure) is the Pressure of a Vapor in equilibrium Tensile strength \sigma_{UTS} or S_U is the Stress at which a material breaks or permanently deforms ^[6] Tungsten has the lowest coefficient of thermal expansion of any pure metal. When the Temperature of a substance changes the energy that is stored in the Intermolecular bonds between atoms changes Alloying small quantities of tungsten with steel greatly increases its toughness. Steel is an Alloy consisting mostly of Iron, with a Carbon content between 0 ^[1]

Isotopes

Main article: Isotopes of tungsten

Naturally occurring tungsten consists of five isotopes whose half-lives are so long that they can be considered stable. Naturally occurring Tungsten ( W) consists of five Isotopes whose half-lives are so long that they can be considered stable. Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides Half-Life (computer-game page here It's already listed in the disambiguation page Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge Theoretically, all five can decay into isotopes of element 72 (hafnium) by alpha emission, but only ¹⁸⁰W has been observed to do so with a half-life of (1. Hafnium (ˈhæfniəm is a Chemical element that has the symbol Hf and Atomic number 72 Alpha decay is a type of radioactive decay in which an Atomic nucleus emits an Alpha particle (two protons and two neutrons bound together into a particle Half-Life (computer-game page here It's already listed in the disambiguation page 8 ± 0. 2)·10¹⁸ yr; on average, this yields about two alpha decays of ¹⁸⁰ in one gram of natural tungsten per year. ^[7] The other naturally occurring isotopes have not been observed to decay, constraining their half-lives to be:^[7]

¹⁸²W, T_1/2 > 8. 3·10¹⁸ yr;

¹⁸³W, T_1/2 > 29·10¹⁸ yr;

¹⁸⁴W, T_1/2 > 13·10¹⁸ yr;

¹⁸⁶W, T_1/2 > 27·10¹⁸ yr.

Another 30 artificial radioisotopes of tungsten have been characterized, the most stable of which are ¹⁸¹W with a half-life of 121. A radionuclide is an Atom with an unstable nucleus, which is a nucleus characterized by excess energy which is available to be imparted either to a newly-created Half-Life (computer-game page here It's already listed in the disambiguation page 2 days, ¹⁸⁵W with a half-life of 75. 1 days, ¹⁸⁸W with a half-life of 69. 4 days, ¹⁷⁸W with a half-life of 21. 6 days, and ¹⁸⁷W with a half-life of 23. 72 h. <ref=isotopes/> All of the remaining radioactive isotopes have half-lives of less than 3 hours, and most of these have half-lives that are less than 8 minutes. Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. ^[7] Tungsten also has 4 meta states, the most stable being ^179mW (T_½ 6. A nuclear isomer is a Metastable state of an Atomic nucleus caused by the excitation of one or more of its Nucleons A nuclear isomer occupies 4 minutes).

Chemical properties

Elemental tungsten resists attack by oxygen, acids, and alkalis. Beta oxidation is the process by which Fatty acids in the form of Acyl-CoA molecules are broken down in Mitochondria and/or in Peroxisomes to In Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are In Chemistry, an alkali (from Arabic: Al-Qaly القلي القالي) is a basic, ionic salt of an Alkali metal ^[8]

Compounds

Main article: Tungsten compounds

The most common formal oxidation state of tungsten is +6, but it exhibits all oxidation states from -1 to +6. In Chemistry, the oxidation state is an indicator of the degree of Oxidation of an Atom in a Chemical compound. ^[8] Tungsten typically combines with oxygen to form the yellow tungstic oxide, WO₃, which dissolves in aqueous alkaline solutions to form tungstate ions, WO₄²⁻. Tungsten(VI oxide, also known as tungsten trioxide or tungstic anhydride, WO3 is a chemical compound containing Oxygen and the transition

Tungsten carbides (W₂C and WC) are produced by heating powdered tungsten with carbon and are some of the hardest carbides, with a melting point of 2770 °C for WC and 2780 degrees C for W₂C. Tungsten carbide, WC, or tungsten semicarbide, W2C, is a chemical compound containing Tungsten and Carbon, similar Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 For the Software development tool targeting the Symbian OS, see Carbide WC is an efficient electrical conductor, but W₂C is not as efficient. In Science and engineering, a conductor is a material which contains movable Electric charges. Tungsten carbide behaves in a manner very similar to that of unalloyed tungsten and is resistant to chemical attack, although it reacts strongly with chlorine to form tungsten hexachloride (WCl₆). Chlorine (ˈklɔriːn from the Greek word 'χλωρóς' ( khlôros, meaning 'pale green' is the Chemical element with Atomic number 17 and Tungsten hexachloride is the Chemical compound with the formula WCl6 ^[1]

Aqueous polyoxoanions

Aqueous tungstate solutions are noted for the formation of heteropoly acids and polyoxometalate anions under neutral and acidic conditions. The term polyoxometalate (abbreviated POM) is applied to an extremely large group of generally anionic clusters with frameworks built from Transition metal Oxo An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge As tungstate is progressively treated with acid, it first yields the soluble, metastable "paratungstate A" anion, W₇O₂₄⁶⁻, which over hours or days converts to the less soluble "paratungstate B" anion, H₂W₁₂O₄₂¹⁰⁻. Metastability is a general scientific concept which describes states of delicate equilibrium An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge Further acidification produces the very soluble metatungstate anion, H₂W₁₂O₄₀⁶⁻, after equilibrium is reached. The metatungstate ion exists as a symmetric cluster of twelve tungsten-oxygen octahedra known as the "Keggin" anion. Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the An octahedron (plural octahedra is a Polyhedron with eight faces Many other polyoxometalate anions exist as metastable species. The inclusion of a different atom such as phosphorus in place of the two central hydrogens in metatungstate produces a wide variety of heteropoly acids, such as phosphotungstic acid H₃P W₁₂O₄₀ in this example. Phosphorus, (ˈfɒsfərəs is the Chemical element that has the symbol P and Atomic number 15 Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 A heteropoly acid is a class of Acid made up of a particular combination of Hydrogen and Oxygen with certain Metals and Non-metals Phosphotungstic acid ( PTA) tungstophosphoric acid ( TPA) is a Heteropoly acid with the chemical formula 3 1240

Biological role

Tungsten is an essential nutrient for some organisms. An essential nutrient is a Nutrient required for normal body functioning that cannot be synthesized by the body and must be obtained from a dietary source

Enzymes called oxidoreductases use tungsten in a way that is similar to molybdenum by using it in a tungsten-pterin complex. Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins In Biochemistry, an oxidoreductase is an Enzyme that catalyzes the transfer of Electrons from one molecule (the reductant, also called the hydrogen Molybdenum (məˈlɪbdənəm from the Greek word for the metal " Lead " is a Group 6 Chemical element with the symbol Mo Pterin is a heterocyclic compound composed of a Pyrazine ring and a Pyrimidine ring (a Pteridine ring system the pyrimidine ring has a

On August 20, 2002, officials representing the U. Events 636 - Battle of Yarmouk: Arab forces led by Khalid ibn al-Walid take control of Syria and Palestine See also 2002 (disambiguation Year 2002 ( MMII) was a Common year starting on Tuesday of the Gregorian calendar. S. -based Centers for Disease Control and Prevention announced that urine tests on leukemia patient families and control group families in the Fallon, Nevada area had shown elevated levels of tungsten in the bodies of both groups. The Centers for Disease Control and Prevention (or CDC) is an agency of the United States Department of Health and Human Services based in unincorporated Urine is a liquid waste product of the body secreted by the Kidneys by a process of filtration from Blood and Excreted through the Urethra. Leukemia or leukaemia (Greek leukos λευκός, "white" aima αίμα, "blood" is a Cancer of the Blood Fallon is a city in Churchill County, located in western Nevada, United States. ^[9] Sixteen recent cases of cancer in children were discovered in the Fallon area, which has now been identified as a cancer cluster (however, the majority of the cancer victims are not longtime residents of Fallon). Cancer (medical term Malignant Neoplasm) is a class of Diseases in which a group of cells display uncontrolled Cancer cluster is a term used by epidemiologists, statisticians, and public health workers to define an occurrence of a greater-than-expected number of Cancer Dr. Carol H. Rubin, a branch chief at the CDC, said data demonstrating a link between tungsten and leukemia is not available at present. ^[10]

Applications

Because of its ability to produce hardness at high temperatures and its high melting point (the second highest of any known element), elemental tungsten is used in many high-temperature applications. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. ^[11] These include light bulb, cathode-ray tube, and vacuum tube filaments, as well as heating elements and nozzles on rocket engines. The incandescent light bulb, incandescent lamp or incandescent light globe is a source of electric Light that works by Incandescence, (a general The cathode ray tube (CRT is a Vacuum tube containing an Electron gun (a source of electrons and a Fluorescent screen with internal or This article is about the electronic device not an evacuated pipe used for experiments in Free-fall. A heating element converts Electricity into Heat through the process of Joule heating. A rocket engine is a Jet engine that uses only Propellant mass for forming its high speed propulsive jet. ^[2] The high melting point also makes tungsten suitable for aerospace and high temperature uses which include electrical, heating, and welding applications, notably in the gas tungsten arc welding process (also called TIG welding). Gas tungsten arc welding ( GTAW) also known as tungsten inert gas (TIG welding, is an Arc welding process that uses a nonconsumable Tungsten Gas tungsten arc welding ( GTAW) also known as tungsten inert gas (TIG welding, is an Arc welding process that uses a nonconsumable Tungsten

Due to its conductive properties, as well as its relative chemical inertia, tungsten is also used in electrodes, and in the emitter tips of field emission electron-beam instruments, such as focused ion beam (FIB) and electron microscopes. An electrode is an Electrical conductor used to make contact with a nonmetallic part of a circuit (e Field emission (FE is the emission of electrons from the surface of a condensed phase into another phase due to the presence of high electric fields Focused ion beam, also known as FIB, is a technique used particularly in the semiconductor and materials science fields for site-specific analysis deposition and ablation of An electron microscope is a type of Microscope that uses Electrons to illuminate a specimen and create an enlarged image In electronics, tungsten is used as an interconnect material in integrated circuits, between the silicon dioxide dielectric material and the transistors. Microchipsjpg|right|thumb|200px|Microchips ( EPROM memory with a transparent window showing the integrated circuit inside The Chemical compound silicon dioxide, also known as silica or silox (from the Latin " Silex " is an Oxide A dielectric is a nonconducting substance ie an insulator. The term was coined by William Whewell in response to a request from Michael Faraday. Additionally, it is used in the manufacture of metallic films, which replace the wiring used in conventional electronics with a coat of tungsten (or molybdenum) on silicon. Molybdenum (məˈlɪbdənəm from the Greek word for the metal " Lead " is a Group 6 Chemical element with the symbol Mo Silicon (ˈsɪlɪkən or /ˈsɪlɪkɒn/ silicium is the Chemical element that has the symbol Si and Atomic number 14 ^[12]

The electronic structure of tungsten makes it one of the main sources for X-ray targets,^[13] and but also for shielding from high-energy radiations (such in radiopharmaceutical industry for shielding radioactive samples of FDG). X-radiation (composed of X-rays) is a form of Electromagnetic radiation. Radiopharmacology is the study and preparation of radiopharmaceuticals, which are radioactive Pharmaceuticals Radiopharmaceuticals are used in the field Fluorodeoxyglucose is a Glucose analog. Its full chemical name is 2-fluoro-2-deoxy-D-glucose, commonly abbreviated to FDG Tungsten powder is used as a filler material in plastic composites, which are used as a nontoxic substitute for lead in bullets, shot, and radiation shields. Plastic is the general common term for a wide range of synthetic or semisynthetic organic solid materials suitable for the manufacture of industrial products Characteristics Lead has a dull luster and is a dense, Ductile, very soft highly A bullet is a solid Projectile propelled by a Firearm or Air gun and is normally made from metal (usually Lead) Since this element's thermal expansion is similar to borosilicate glass, it is used for making glass-to-metal seals. Borosilicate glass is a type of Glass with the main glass-forming constituents Silica and Boron oxide. ^[6]

The hardness and density of tungsten are applied in obtaining heavy metal alloys. An alloy is a Solid solution or Homogeneous mixture of two or more elements, at least one of which is a Metal, which itself has A good example is the high speed steel, which may contain as much as 18% tungsten. High speed steel (often abbreviated HSS, sometimes HS) is a material usually used in the manufacture of machine Tool bits and other cutters ^[14] Superalloys containing tungsten like Hastelloy and Stellite are used in turbine blades and wear resistant parts and coatings. A superalloy, or high-performance alloy, is an Alloy that exhibits excellent mechanical strength and creep resistance at high temperatures good surface Hastelloy is the registered Trademark name of Haynes International, Inc Stellite alloy is a range of Cobalt - Chromium Alloys designed for Wear resistance A turbine is a rotary Engine that extracts Energy from a Fluid flow Applications requiring its high density include heat sinks, weights, counterweights, ballast keels for yachts, tail ballast for commercial aircraft, and as ballast in high level race cars in series such as NASCAR and Formula 1. A heat sink (or heatsink) is an environment or object that absorbs and dissipates heat from another object using Thermal contact (either direct or radiant The National Association for Stock Car Auto Racing ( NASCAR) is the largest sanctioning body of Stock cars in the United States. In armaments, tungsten, usually alloyed with nickel and iron or cobalt to form heavy alloys, is used in kinetic energy penetrators as an alternative to depleted uranium but may also be used in cannon shells, grenades and missiles to create super-sonic shrapnel. A kinetic energy penetrator (also known as a KE weapon) is a type of Ammunition which like a Bullet, does not contain Explosives and uses Depleted uranium (DU is Uranium primarily composed of the Isotope Uranium-238 (U-238 High-density alloys of tungsten may be used in darts (to allow for a smaller diameter and thus tighter groupings) or for fishing lures (tungsten bead heads allow to sink the fly rapidly). Darts refers to a variety of related games in which darts are thrown at a circular target (dartboard hung on a wall In terms of Recreational fishing, a lure is an object attached to the end of the Fishing line and designed to resemble and move like an item of Fish Prey Some types of strings for musical instruments are wound with tungsten wires. A string is the vibrating element that is the source of vibration in String instruments such as the Guitar, Harp, Piano, and members Its density, similar to that of gold, allows tungsten to be used in jewelry as an alternative to gold or platinum. Gold (ˈɡoʊld is a Chemical element with the symbol Au (from its Latin name aurum) and Atomic number 79 Platinum (ˈplætɪnəm is a Chemical element with the Atomic symbol Pt and an Atomic number of 78 ^[2] Its hardness makes it ideal for rings that will resist scratching, are hypoallergenic and will not need polishing, which is especially useful in designs with a brushed finish. A finger ring is a band worn as a type of ornamental Jewellery around a finger it is the most common current meaning of the word ring. Hypoallergenic is a term coined by advertisers (based on the Greek prefix Hypo meaning "below normal" or "slightly" and first used in a cosmetics ^[15]

Tungsten chemical compounds are used in catalysts, inorganic pigments (i. Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst e. tungsten oxides), and also as high-temperature lubricants (tungsten disulfide). Tungsten has several oxidation states and therefore oxides Tungsten(III oxide Tungsten(IV oxide, also known as tungsten dioxide A lubricant (sometimes referred to as a "Lube" is a substance (often a liquid introduced between two moving surfaces to reduce the Friction between them improving Tungsten(IV sulfide is the Chemical compound with the formula W[[Sulfur S2]] Tungsten carbide (WC) is used to make wear-resistant abrasives and cutters and knives for drills, circular saws, milling and turning tools used by the metalworking, woodworking, mining, petroleum and construction industries. Tungsten carbide, WC, or tungsten semicarbide, W2C, is a chemical compound containing Tungsten and Carbon, similar An abrasive is a material often a Mineral, that is used to shape or finish a workpiece through rubbing which leads to part of the workpiece being worn away The circular saw is a Metal disc or Blade with Saw Teeth on the edge as well as the Machine that causes the disk to A milling machine is a Machine tool used for the shaping of Metal and other Solid Materials. Metal lathe or metalworking lathe are generic terms for any of a large class of Lathes designed for precisely Machining relatively Mining is the extraction of valuable Minerals or other geological materials from the earth usually (but not always from an Ore body Petroleum ( L petroleum, from Greek πετρέλαιον, lit ^[1] Tungsten oxides are used in ceramic glazes and calcium/magnesium tungstates are used widely in fluorescent lighting. The word ceramic is derived from the Greek word κεραμικός ( keramikos) Calcium (ˈkælsiəm is the Chemical element with the symbol Ca and Atomic number 20 Magnesium (mægˈniːziəm is a Chemical element with the symbol Mg, Atomic number 12 Atomic weight 24 A fluorescent lamp or fluorescent tube is a Gas-discharge lamp that uses Electricity to excite mercury Vapor. Crystal tungstates are used as scintillation detectors in nuclear physics and nuclear medicine. The tungstate Ion is WO42&minus A tungstate (compound is a compound containing the tungstate ion or more complicated Polymeric A scintillator is a substance that absorbs high-energy (ie Ionizing) electromagnetic or charged Particle radiation then in response fluoresces Nuclear physics is the field of Physics that studies the building blocks and interactions of Atomic nuclei. Nuclear medicine is a branch of Medicine and Medical imaging that uses the nuclear properties of matter in diagnosis and therapy Other salts that contain tungsten are used in the chemical and tanning industries. Tanning is the process of converting Putrescible skin into non-putrescible Leather, usually with Tannin, an Acidic Chemical compound ^[6]

Production

Tungsten is found in the minerals wolframite (iron-manganese tungstate, FeWO₄/MnWO₄), scheelite (calcium tungstate, (CaWO₄), ferberite and hübnerite. A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition a highly ordered atomic structure and specific Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 Manganese (ˈmæŋgəniːz is a Chemical element, designated by the symbol Mn. Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Scheelite is a Calcium Tungstate Mineral with the Chemical formula Ca[[tungsten W]] O 4 Calcium (ˈkælsiəm is the Chemical element with the symbol Ca and Atomic number 20 Ferberite is the iron endmember of the manganese - iron Wolframite Solid solution series Hübnerite or hubnerite is a Mineral consisting of Manganese Tungstate (chemical formula MnWO4 These are mined and used to produce about 37,400 tons of tungsten concentrates every year. ^[16] Over 75% of this production came from China, while most of the remaining production is done in Austria, Bolivia, Portugal, and Russia, while United States produces none. China ( Wade-Giles ( Mandarin) Chung¹kuo² is a cultural region, an ancient Civilization, and depending on perspective a National The United States of America —commonly referred to as the ^[16]

The extraction of tungsten has several stages, the ore eventually being converted to tungsten (VI) oxide (WO₂), which is heated with hydrogen or carbon, producing powdered tungsten. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 ^[17] It can be used in that state or converted into solid bars.

Tungsten can also be extracted by hydrogen reduction of WF₆ (WF₆ + 3H₂ = W + 6HF) or pyrolytic decomposition (WF₆ + energy = W + 3F₂). Pyrolysis is the Chemical decomposition of organic materials by heating in the absence of Oxygen or any other reagents except possibly Steam ^[12]

History

In 1781, Carl Wilhelm Scheele ascertained that a new acid could be made from scheelite (at the time named tungstenite): tungstic acid. Carl Wilhelm Scheele (9 December 1742 &ndash 21 May 1786 was a German - Swedish pharmaceutical chemist born in Stralsund, Western Pomerania, In Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are Tungstic acid refers to hydrated forms of Tungsten trioxide, WO3 Scheele and Torbern Bergman suggested that it could be possible to obtain a new metal by reducing this acid. Torbern Olof Bergman ( March 20, 1735 Katrineberg, Sweden, &ndash July 8, 1784 Medevi, Sweden) was ^[17] In 1783 José and Fausto Elhuyar found an acid made from wolframite that was identical to tungstic acid. Juan José Elhuyar Lubize ( June 15, 1754 &ndash September 20, 1796) was a Spanish Basque Chemist and Mineralogist Fausto de Elhuyar ( October 11, 1755 - February 6, 1833) was a Spanish Basque Chemist, and the Joint discoverer In Spain later that year the brothers succeeded in isolating tungsten through reduction of this acid with charcoal. Spain () or the Kingdom of Spain (Reino de España is a country located mostly in southwestern Europe on the Iberian Peninsula. Charcoal' is the blackish residue consisting of impure Carbon obtained by removing water and other volatile constituents from Animal and Vegetation They are credited with the discovery of the element. ^[18][19]

In World War II, tungsten played an enormous role in background political dealings. Portugal, as the main European source of the element, was put under pressure from both sides, because of its sources of wolframite ore. Portugal, officially the Portuguese Republic (República Portuguesa is a country on the Iberian Peninsula. The resistance to high temperatures, as well as the extreme strength of its alloys, made the metal into a very important raw material for the weaponry industry.

See also

• Field emission gun
• Oliver Sacks: "Uncle Tungsten: Memories of a Chemical Boyhood"

References

• DC/AC Circuits and Electronics: Principles & Applications by Robert K. A field emission gun is a type of Electron gun in which the emitter tip is held at several kilovolts negative Potential relative to a nearby Electrode, Oliver Wolf Sacks, CBE (born July 9, 1933, London is a British Neurologist residing in the United States who has written popular books about Uncle Tungsten Memories of a Chemical Boyhood is a Memoir by Oliver Sacks about his childhood published in 2001. Herrick, Published by Delmar Learning 2003 for Purdue University

1. ^ ^{a b c d} Daintith, John. Facts on File Dictionary of Chemistry. 4th ed. New York, New York: Checkmark Books, 2005
2. ^ ^{a b c d e} Stwertka, Albert A Guide to the elements. 2nd ed. New York: Oxford University Press, 2002.
3. ^ J McMaster and John H Enemark (1998). "The active sites of molybdenum- and tungsten-containing enzymes". Current Opinion in Chemical Biology 2 (2): 201–207. doi:10.1016/S1367-5931(98)80061-6. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
4. ^ "Molybdenum and tungsten in biology" (2002). Trends in Biochemical Sciences 27 (7): 360–367. doi:10.1016/S0968-0004(02)02107-2. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
5. ^ Peter van der Krogt. Wolframium Wolfram Tungsten. Elementymology & Elements Multidict. Retrieved on 2008-05-09. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 1457 BC - Battle of Megiddo (15th century BC between Thutmose III and a large Canaanite coalition under the King of
6. ^ ^{a b c} Tungsten. Los Alamos National Laboratory (2003-12-15). Year 2003 ( MMIII) was a Common year starting on Wednesday of the Gregorian calendar. Events 533 - Byzantine general Belisarius defeats the Vandals, commanded by King Gelimer, at the Battle of Retrieved on 2008-05-09. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 1457 BC - Battle of Megiddo (15th century BC between Thutmose III and a large Canaanite coalition under the King of
7. ^ ^{a b c} Alejandro Sonzogni. Interactive Chart of Nuclides. Brookhaven National Laboratory. Retrieved on 2008-06-06. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 1508 - Maximilian I Holy Roman Emperor, is defeated in Friulia by Venetian forces; he is forced to sign a three-year
8. ^ ^{a b} Emsley, John E. The elements. 2nd ed. New York: Oxford University Press, 1991
9. ^ Cross-Sectional Exposure Assessment of Environmental Contaminants in Churchill County, Nevada. Centers for Disease Control and Prevention (2003-02-06). Year 2003 ( MMIII) was a Common year starting on Wednesday of the Gregorian calendar. Events 46 BC - Julius Caesar defeats the combined army of Pompeian followers and Numidians under Metellus Scipio Retrieved on 2008-05-09. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 1457 BC - Battle of Megiddo (15th century BC between Thutmose III and a large Canaanite coalition under the King of
10. ^ ------?---------. Reno Gazette-Journal. Retrieved on unavailable.
11. ^ DeGarmo, E. Paul. Materials and Processes in Manufacturing. 5th ed. New York, New York: MacMillan Publishing, 1979.
12. ^ ^{a b} Schey, John A. Introduction to Manufacturing Processes. 2nd ed. McGraw-Hill, Inc, 1987.
13. ^ http://www.patentstorm.us/patents/6428904/description.html
14. ^ http://www.azom.com/details.asp?ArticleID=1264
15. ^ How to Make Convincing Fake-Gold Bars
16. ^ ^{a b} http://minerals.usgs.gov/minerals/pubs/commodity/tungsten/680400.pdf
17. ^ ^{a b} Saunders, Nigel. Tungsten and the Elements of Groups 3 to 7. Chicago, Illinois: Heinemann Library, 2003.
18. ^ http://www.itia.info/FileLib/ITIA_Newsletter_June05.pdf
19. ^ http://www.itia.info/FileLib/ITIA_Newsletter_December05.pdf

External links

• Tungsten Disulfide Applications WS2
• WebElements.com – Tungsten
• Properties, Photos, History, MSDS
• ScienceLab.com – Tungsten
• Picture in the collection from Heinrich Pniok
• Elementymology & Elements Multidict by Peter van der Krogt – Tungsten
• Detection of the Natural Alpha Decay of Tungsten
• International Tungsten Industry Association

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