76 rhenium ← osmium → iridium Ru ↑ Os ↓ Hs Periodic Table - Extended Periodic Table
General
Name, Symbol, Number	osmium, Os, 76
Chemical series	transition metals
Group, Period, Block	8, 6, d
Appearance	silvery, blue cast
Standard atomic weight	190.23(3) g·mol−1
Electron configuration	[Xe] 4f14 5d6 6s2
Electrons per shell	2, 8, 18, 32, 14, 2
Physical properties
Phase	solid
Density (near r.t.)	22.61 g·cm−3
Liquid density at m.p.	20 g·cm−3
Melting point	3306 K (3033 °C, 5491 °F)
Boiling point	5285 K (5012 °C, 9054 °F)
Heat of fusion	57.85 kJ·mol−1
Heat of vaporization	738 kJ·mol−1
Heat capacity	(25 °C) 24.7 J·mol−1·K−1
Vapor pressure P(Pa) 1 10 100 1 k 10 k 100 k at T(K) 3160 3423 3751 4148 4638 5256
Atomic properties
Crystal structure	hexagonal
Oxidation states	8, 7, 6, 5, 4, 3, 2, 1, −1, −2 (mildly acidic oxide)
Electronegativity	2.2 (scale Pauling)
Ionization energies	1st: 840 kJ/mol
	2nd: 1600 kJ/mol
Atomic radius	130 pm
Atomic radius (calc.)	185 pm
Covalent radius	128 pm
Miscellaneous
Magnetic ordering	?
Electrical resistivity	(0 °C) 81.2 nΩ·m
Thermal conductivity	(300 K) 87.6 W·m−1·K−1
Thermal expansion	(25 °C) 5.1 µm·m−1·K−1
Speed of sound (thin rod)	(20 °C) 4940 m/s
Shear modulus	222 GPa
Poisson ratio	0.25
Bulk modulus	462 GPa
Mohs hardness	7.0
Brinell hardness	3920 MPa
CAS registry number	7440-04-2
Selected isotopes
Main article: Isotopes of osmium iso NA half-life DM DE (MeV) DP 184Os 0.02% >5.6×1013y α 2.966 180W 185Os syn 93.6 d ε 1.013 185Re 186Os 1.59% 2.0×1015y α 2.822 182W 187Os 1.96% Os is stable with 111 neutrons 188Os 13.24% Os is stable with 112 neutrons 189Os 16.15% Os is stable with 113 neutrons 190Os 26.26% Os is stable with 114 neutrons 191Os syn 15.4 d β- 0.314 191Ir 192Os 40.78% Os is stable with 116 neutrons 193Os syn 30.11 d β- 1.141 193Ir 194Os syn 6 y β- 0.097 194Ir
References

Osmium (IPA: /ˈɒzmiəm/) is a chemical element that has the symbol Os and atomic number 76. Osmium is a hard, brittle, blue-gray or blue-black transition metal in the platinum family, and is one of the densest natural elements, competing for this status with iridium. Osmium is used in alloys with platinum, iridium and other platinum group metals. Osmium is found in nature as an alloy in platinum ore. Alloys of osmium are employed in fountain pen tips, electrical contacts and in other applications where extreme durability and hardness are needed. General Name, Symbol, Number rhenium, Re, 75 Chemical series transition metals Group, Period, Block 7, 6, d Appearance grayish white Standard atomic weight 186. ... This article is about the chemical element. ... General Name, Symbol, Number Ruthenium, Ru, 44 Chemical series transition metals Group, Period, Block 8, 5, d Appearance silvery white metallic Atomic mass 101. ... General Name, Symbol, Number hassium, Hs, 108 Chemical series transition metals Group, Period, Block 8, 7, d Appearance unknown, probably silvery white or metallic gray Atomic mass (269) g/mol Electron configuration perhaps [Rn] 5f14 6d6 7s2 (guess based on osmium) Electrons per shell 2, 8, 18, 32, 32, 14... Original Image: media:Os-TableImage-BIG.png File links The following pages link to this file: Osmium User:Femto/elements e9 Categories: GFDL images ... This is a standard display of the periodic table of the elements. ... An extended periodic table was suggested by Glenn T. Seaborg in 1969. ... This is a list of chemical elements, sorted by name and color coded according to type of element. ... A table of chemical elements ordered by atomic number and color coded according to type of element. ... A group, also known as a family, is a vertical column in the periodic table of the chemical elements. ... In chemistry, the term transition metal (sometimes also called a transition element) has two possible meanings: It commonly refers to any element in the d-block of the periodic table, including zinc, cadmium and mercury. ... A group, also known as a family, is a vertical column in the periodic table of the chemical elements. ... 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. ... A Group 8 element is an element in periodic table group 8 (IUPAC style) in the periodic table, which consists of: Iron (26) Ruthenium (44) Osmium (76) Hassium (108) All of these elements are classed in Group 8 because their valence shell holds four electrons. ... 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. ... D Block is a rap group based in Yonkers, New York. ... Color is an important part of the visual arts. ... Image File history File linksMetadata Download high-resolution version (489x720, 280 KB)Photograph of two 5-gram osmium pellets from the Justin Urgitis collection. ... The atomic mass (ma) is the mass of an atom at rest, most often expressed in unified atomic mass units. ... To help compare different orders of magnitude we list here masses between 60. ... Hydrogen = 1 List of Elements in Atomic Number Order. ... Electron atomic and molecular orbitals In atomic physics and quantum chemistry, the electron configuration is the arrangement of electrons in an atom, molecule, or other physical structure (, a crystal). ... General Name, Symbol, Number xenon, Xe, 54 Chemical series noble gases Group, Period, Block 18, 5, p Appearance colorless Standard atomic weight 131. ... For other uses, see Electron (disambiguation). ... Example of a sodium electron shell model An electron shell, also known as a main energy level, is a group of atomic orbitals with the same value of the principal quantum number n. ... 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 (i. ... For other uses, see Solid (disambiguation). ... For other uses, see Density (disambiguation). ... For other uses, see Room temperature (disambiguation). ... For other uses, see Density (disambiguation). ... The melting point of a crystalline solid is the temperature range at which it changes state from solid to liquid. ... The melting point of a crystalline solid is the temperature range at which it changes state from solid to liquid. ... For other uses, see Kelvin (disambiguation). ... Celsius is, or relates to, the Celsius temperature scale (previously known as the centigrade scale). ... For other uses, see Fahrenheit (disambiguation). ... Italic text This article is about the boiling point of liquids. ... For other uses, see Kelvin (disambiguation). ... Celsius is, or relates to, the Celsius temperature scale (previously known as the centigrade scale). ... For other uses, see Fahrenheit (disambiguation). ... Standard enthalpy change of fusion of period three. ... The joule per mole (symbol: J·mol-1) is an SI derived unit of energy per amount of material. ... The standard enthalpy change of vaporization, ΔvHo, also (less correctly) known as the heat of vaporization is the energy required to transform a given quantity of a substance into a gas. ... The joule per mole (symbol: J·mol-1) is an SI derived unit of energy per amount of material. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Vapor pressure is the pressure of a vapor in equilibrium with its non-vapor phases. ... Enargite crystals In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... The oxidation number of an element in a molecule or complex is the charge that it would have if all the ligands (basically, atoms that donate electrons) were removed along with the electron pairs that were shared with the central atom[1]. It means that the oxidation number is the... For other uses, see Acid (disambiguation). ... Electronegativity is a measure of the ability of an atom or molecule to attract electrons in the context of a chemical bond. ... The ionization potential, ionization energy or EI of an atom or molecule is the energy required to remove one mole of electrons from one mole of isolated gaseous atoms or ions. ... The joule per mole (symbol: J·mol-1) is an SI derived unit of energy per amount of material. ... Atomic radius: Ionic radius Covalent radius Metallic radius van der Waals radius edit Atomic radius, and more generally the size of an atom, is not a precisely defined physical quantity, nor is it constant in all circumstances. ... You have big harry skanky balls ... One picometre is defined as 1x10-12 metres, in standard units. ... You have big harry skanky balls ... Atomic radius: Ionic radius Covalent radius Metallic radius van der Waals radius edit The covalent radius, rcov, is a measure of the size of atom which forms part of a covalent bond. ... You have big harry skanky balls ... For other senses of this word, see magnetism (disambiguation). ... Electrical resistivity (also known as specific electrical resistance) is a measure of how strongly a material opposes the flow of electric current. ... K value redirects here. ... During heat transfer, the energy that is stored in the intermolecular bonds between atoms changes. ... This page is about the physical speed of sound waves in a medium. ... Metre per second (U.S. spelling: meter per second) is an SI derived unit of both speed (scalar) and velocity (vector), defined by distance in metres divided by time in seconds. ... In materials science, shear modulus, G, or sometimes S or μ, sometimes referred to as the modulus of rigidity, is defined as the ratio of shear stress to the shear strain:[1] where = shear stress; force acts on area ; = shear strain; length changes by amount . ... Figure 1: Rectangular specimen subject to compression, with Poissons ratio circa 0. ... The bulk modulus (K) of a substance essentially measures the substances resistance to uniform compression. ... This article or section does not cite any references or sources. ... The Brinell scale characterises 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. ... Osmium (Os) Standard atomic mass: 190. ... For other uses, see Isotope (disambiguation). ... Natural abundance refers to the prevalence of different isotopes of an element as found in nature. ... Half-Life For a quantity subject to exponential decay, the half-life is the time required for the quantity to fall to half of its initial value. ... Radioactive decay is the process in which an unstable atomic nucleus loses energy by emitting radiation in the form of particles or electromagnetic waves. ... The decay energy is the energy released by a nuclear decay. ... The electronvolt (symbol eV) is a unit of energy. ... In nuclear physics, a decay product, also known as a daughter product, is a nuclide resulting from the radioactive decay of a parent or precursor nuclide. ... A year (from Old English gÄ“r) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... Alpha decay Alpha decay is a type of radioactive decay in which an atom emits an alpha particle (two protons and two neutrons bound together into a particle identical to a helium nucleus) and transforms (or decays) into an atom with a mass number 4 less and atomic number 2... For other uses, see Tungsten (disambiguation). ... 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 a very short period of time. ... Electron capture is a decay mode for isotopes that will occur when there are too many protons in the nucleus of an atom, and there isnt enough energy to emit a positron; however, it continues to be a viable decay mode for radioactive isotopes that can decay by positron... General Name, Symbol, Number rhenium, Re, 75 Chemical series transition metals Group, Period, Block 7, 6, d Appearance grayish white Standard atomic weight 186. ... A year (from Old English gÄ“r) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... Alpha decay Alpha decay is a type of radioactive decay in which an atom emits an alpha particle (two protons and two neutrons bound together into a particle identical to a helium nucleus) and transforms (or decays) into an atom with a mass number 4 less and atomic number 2... For other uses, see Tungsten (disambiguation). ... Stable isotopes are chemical isotopes that are not radioactive. ... This article or section does not adequately cite its references or sources. ... Stable isotopes are chemical isotopes that are not radioactive. ... This article or section does not adequately cite its references or sources. ... Stable isotopes are chemical isotopes that are not radioactive. ... This article or section does not adequately cite its references or sources. ... Stable isotopes are chemical isotopes that are not radioactive. ... This article or section does not adequately cite its references or sources. ... 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 a very short period of time. ... In nuclear physics, beta decay (sometimes called neutron decay) is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted. ... This article is about the chemical element. ... Stable isotopes are chemical isotopes that are not radioactive. ... This article or section does not adequately cite its references or sources. ... 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 a very short period of time. ... In nuclear physics, beta decay (sometimes called neutron decay) is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted. ... This article is about the chemical element. ... 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 a very short period of time. ... In nuclear physics, beta decay (sometimes called neutron decay) is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted. ... This article is about the chemical element. ... Recommended values for many properties of the elements, together with various references, are collected on these data pages. ... Osmium may refer to: Osmium, the chemical element Osmium (band), a heavy metal band Osmium (album), the debut album of Parliament This is a disambiguation page: a list of articles associated with the same title. ... Articles with similar titles include the NATO phonetic alphabet, which has also informally been called the “International Phonetic Alphabet”. For information on how to read IPA transcriptions of English words, see IPA chart for English. ... The periodic table of the chemical elements A chemical element, or element, is a type of atom that is defined 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 number) is the number of protons found in the nucleus of an atom. ... In chemistry, the term transition metal (sometimes also called a transition element) has two possible meanings: It commonly refers to any element in the d-block of the periodic table, including zinc, cadmium and mercury. ... The platinum group or platinum family is a group of six metal elements with similar physical and chemical properties. ... This article is about the chemical element. ... An alloy is a homogeneous hybrid of two or more elements, at least one of which is a metal, and where the resulting material has metallic properties. ... General Name, Symbol, Number platinum, Pt, 78 Chemical series transition metals Group, Period, Block 10, 6, d Appearance grayish white Standard atomic weight 195. ... This article is about the chemical element. ... A fountain pen is a writing instrument, more specifically a pen, that contains a reservoir of water-based ink that is fed to a nib through a feed via a combination of gravity and capillary action. ...

Notable characteristics

Osmium in a metallic form is extremely dense, blue-white, brittle, and lustrous even at high temperatures, but proves to be extremely difficult to make. Powdered osmium is easier to make, but powdered osmium exposed to air leads to the formation of osmium tetroxide (OsO₄), which is toxic. The oxide is also a powerful oxidizing agent, has a strong smell and boils at 130°C. This article is about metallic materials. ... For other uses, see Density (disambiguation). ... The chemical compound osmium tetroxide (OsO4), also known as osmium tetraoxide, osmium(VIII) oxide, or osmic acid, is an oxide of the element osmium. ... General Name, symbol, number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, period, block 16, 2, p Appearance colorless (gas) pale blue (liquid) Standard atomic weight 15. ... The most fundamental reactions in chemistry are the redox processes. ... Celsius is, or relates to, the Celsius temperature scale (previously known as the centigrade scale). ...

Due to its very high density osmium is generally considered to be the densest known element, narrowly defeating iridium. However, calculations of density from the space lattice may produce more reliable data for these elements than actual measurements and give a density of 22650 kg/m³ for iridium versus 22610 kg/m³ for osmium. Definitive selection between the two is therefore not possible at this time. If one distinguishes different isotopes, then the highest density ordinary substance would be ¹⁹²Os. The extraordinary density of osmium is a consequence of the lanthanide contraction. For other uses, see Density (disambiguation). ... This article is about the chemical element. ... Rose des Sables (Sand Rose), formed of gypsum crystals In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... Kilogram per cubic metre is the SI measure of density and is represented as kg/m³, where kg stands for kilogram and m³ stands for cubic metre. ... This article or section is in need of attention from an expert on the subject. ...

Osmium has a very low compressibility. Correspondingly, its bulk modulus is extremely high—commonly quoted as 462 GPa, which is higher than that of diamond but lower than that of aggregated diamond nanorods—although there is some debate in the academic community about whether it is in fact this high. A paper by Cynn et al ^[1] reported that osmium had this bulk modulus, based on an experimental result, but other authors have cast doubt upon this (^[2] and references therein). Fluid Dynamics Compressibility (physics) is a measure of the relative volume change of fluid or solid as a response to a pressure (or mean stress) change: . For a gas the magnitude of the compressibility depends strongly on whether the process is adiabatic or isothermal, while this difference is small in... The bulk modulus (K) of a substance essentially measures the substances resistance to uniform compression. ... This article is about the mineral. ... Aggregated diamond nanorods, or ADNRs, are an allotrope of carbon believed to be the least compressible material known to humankind, as measured by its isothermal bulk modulus; aggregated diamond nanorods have a modulus of 491 gigapascals (GPa), while a conventional diamond has a modulus of 442 GPa. ...

Osmium metal has the highest melting point and the lowest vapor pressure of the platinum family. Common oxidation states of osmium are +4 and +3, but oxidation states from +1 to +8 are observed. The melting point of a crystalline solid is the temperature range at which it changes state from solid to liquid. ... Vapor pressure is the pressure of a vapor in equilibrium with its non-vapor phases. ... The platinum group or platinum family is a group of six metal elements with similar physical and chemical properties. ... In chemistry, the oxidation state is an indicator of the degree of oxidation of an atom in a chemical compound. ...

Applications

Because of the volatility and extreme toxicity of its oxide, osmium is rarely used in its pure state, and is instead often alloyed with other metals that are used in high-wear applications. Osmium alloys such as osmiridium are very hard and, along with other platinum group metals, is almost entirely used in alloys employed in the tips of fountain pens, phonograph needles, instrument pivots, and electrical contacts, as they can resist wear from frequent use. An alloy is a homogeneous hybrid of two or more elements, at least one of which is a metal, and where the resulting material has metallic properties. ... Osmiridium is an alloy of osmium and iridium with a trace of platinum and rhodium, found naturally or man-made. ... A fountain pen is a writing instrument, more specifically a pen, that contains a reservoir of water-based ink that is fed to a nib through a feed via a combination of gravity and capillary action. ... “Tonearm” redirects here. ...

Osmium tetroxide has been used in fingerprint detection and in staining fatty tissue for microscope slides. As a strong oxidant, it cross-links lipids mainly by reacting with unsaturated carbon-carbon bonds, and thereby both fixes biological membranes in place in tissue samples and simultaneously stains them, since osmium atoms are extremely electron dense, making OsO₄ an important stain for transmission electron microscopy (TEM) studies of many biological materials. An alloy of 90% platinum and 10% osmium (90/10) is used in surgical implants such as pacemakers and replacement pulmonary valves. A macro shot of a palm and the base of several fingers; as seen here, debris can gather between the ridges. ... For other uses, see FAT. Fats consist of a wide group of compounds that are generally soluble in organic solvents and largely insoluble in water. ... Staining is a biochemical technique of adding a class-specific (DNA, proteins, lipids, carbohydrates) dye to a substrate to qualify or quantify the presence of a specific compound. ... A section of a cell of Bacillus subtilis, taken with a Tecnai T-12 TEM. The scale bar is 200nm. ... An implant is an artificial device made to replace and act as a missing biological structure. ... A pacemaker, scale in centimeters A pacemaker (or artificial pacemaker, so as not to be confused with the hearts natural pacemaker) is a medical device which uses electrical impulses, delivered by electrodes contacting the heart muscles, to regulate the beating of the heart. ... The heart and lungs (from an older edition of Grays Anatomy) The lung is an organ belonging to the respiratory system and interfacing to the circulatory system of air-breathing vertebrates. ...

The tetroxide (and a related compound, potassium osmate) are important oxidants for chemical synthesis, despite being very poisonous.

In 1898 an Austrian chemist, Auer von Welsbach, developed the Oslamp with a filament made of osmium, which he introduced commercially in 1902. After only a few years, osmium was replaced by the more stable metal tungsten (originally known as wolfram). Tungsten has the highest melting point of any metal, and using it in light bulbs increases the luminous efficacy and life of incandescent lamps. Carl Auer von Welsbach ( 9 September 1858 - 8 April 1929) was an Austrian scientist and inventor who had a talent for not only discovering advances, but turning them into commercially successful products. ... For other uses, see Tungsten (disambiguation). ...

The light bulb manufacturer OSRAM (founded in 1906 when three German companies; Auer-Gesellschaft, AEG and Siemens & Halske combined their lamp production facilities), derived its name from the elements of OSmium and wolfRAM. This article or section does not cite its references or sources. ...

History

Osmium (Greek osme meaning "a smell") was discovered in 1803 by Smithson Tennant and William Hyde Wollaston in London, England. 1803 was a common year starting on Saturday (see link for calendar). ... Smithson Tennant (November 30, 1761 - February 22, 1815) was an English chemist. ... William Hyde Wollaston William Hyde Wollaston FRS (August 6, 1766 – December 22, 1828) was an English chemist and physicist who is famous for discovering two chemical elements and for developing a way to process platinum ore. ... This article is about the capital of England and the United Kingdom. ... For other uses, see England (disambiguation). ...

Wollaston and Tennant were looking for a way to purify platinum by dissolution of native platinum ore in aqua regia. Large amounts of insoluble black powder remained as a byproduct of this operation. Solvation is the attraction and association of molecules of a solvent with molecules or ions of a solute. ... General Name, Symbol, Number platinum, Pt, 78 Chemical series transition metals Group, Period, Block 10, 6, d Appearance grayish white Standard atomic weight 195. ... Iron ore (Banded iron formation) Manganese ore Lead ore Gold ore An ore is a volume of rock containing components or minerals in a mode of occurrence which renders it valuable for mining. ... Freshly prepared aqua regia is colorless, but it turns orange within seconds. ...

Wollaston concentrated on the soluble portion and discovered palladium (in 1802) and rhodium (in 1804), while Tennant examined the insoluble residue. In the summer of 1803, Tennant identified two new elements; osmium and iridium. Discovery of the new elements was documented in a letter to the Royal Society on June 21, 1804. For other uses, see Palladium (disambiguation). ... --69. ... General Name, Symbol, Number rhodium, Rh, 45 Chemical series transition metals Group, Period, Block 9, 5, d Appearance silvery white metallic Standard atomic weight 102. ... 1804 was a leap year starting on Sunday (see link for calendar). ... 1803 was a common year starting on Saturday (see link for calendar). ... This article is about the chemical element. ... For other uses, see Royal Society (disambiguation). ... is the 172nd day of the year (173rd in leap years) in the Gregorian calendar. ... 1804 was a leap year starting on Sunday (see link for calendar). ...

Occurrence

Turkey, with 127,000 tons, has the world's largest known reserve of osmium. Bulgaria also has substantial reserves of about 2500 tons. This transition metal is also found in iridiosmium, a naturally occurring alloy of iridium and osmium, and in platinum-bearing river sands in the Ural Mountains, and North and South America. It also occurs in nickel-bearing ores found in the Sudbury, Ontario region with other platinum group metals. Even though the quantity of platinum metals found in these ores is small, the large volume of nickel ores processed makes commercial recovery possible. Please wikify (format) this article as suggested in the Guide to layout and the Manual of Style. ... General Name, Symbol, Number platinum, Pt, 78 Chemical series transition metals Group, Period, Block 10, 6, d Appearance grayish white Standard atomic weight 195. ... Map of the Ural Mountains The Ural Mountains (Russian: , Uralskiye gory) (also known as the Urals, the Riphean Mountains in Greco-Roman antiquity, and known as the Stone Belt) are a mountain range that runs roughly north and south through western Russia. ... North America North America is a continent[1] in the Earths northern hemisphere and (chiefly) western hemisphere. ... South America South America is a continent crossed by the equator, with most of its area in the Southern Hemisphere. ... For other uses, see Nickel (disambiguation). ... Greater Sudbury (2001 census population 155,219) is a city in Northern Ontario. ...

Value

Osmium is quite valuable, costing about US$400 per troy ounce.^[3] One of the stable isotopes, ¹⁸⁷Os, is worth about $25,000 per gram.^[4] Troy weight is a system of units of mass customarily used for precious metals and gemstones. ... BIC pen cap, about 1 gram. ...

Compounds

See also osmium compounds. Osmium tetroxide OsO₄ The chemical compound osmium tetroxide (OsO4), also known as osmium tetraoxide, osmium(VIII) oxide, or osmic acid, is an oxide of the element osmium. ...

Isotopes

Main article: isotopes of osmium

Osmium has seven naturally-occurring isotopes, 5 of which are stable: ¹⁸⁷Os, ¹⁸⁸Os, ¹⁸⁹Os, ¹⁹⁰Os, and (most abundant) ¹⁹²Os. The other two, ¹⁸⁴Os and ¹⁸⁶Os, have enormously long half-lives and for practical purposes can be considered to be stable as well. ¹⁸⁷Os is the daughter of ¹⁸⁷Re (half-life 4.56 x 10¹⁰ years) and is most often measured in an ¹⁸⁷Os/¹⁸⁸Os ratio. This ratio, as well as the ¹⁸⁷Re/¹⁸⁷Os ratio, have been used extensively in dating terrestrial as well as meteoric rocks. It has also been used to measure the intensity of continental weathering over geologic time and to fix minimum ages for stabilization of the mantle roots of continental cratons. However, the most notable application of Os in dating has been in conjunction with iridium, to analyze the layer of shocked quartz along the K-T boundary that marks the extinction of the dinosaurs 65 million years ago. Osmium (Os) Standard atomic mass: 190. ... For other uses, see Isotope (disambiguation). ... Half-Life For a quantity subject to exponential decay, the half-life is the time required for the quantity to fall to half of its initial value. ... General Name, Symbol, Number rhenium, Re, 75 Chemical series transition metals Group, Period, Block 7, 6, d Appearance grayish white Standard atomic weight 186. ... Half-Life For a quantity subject to exponential decay, the half-life is the time required for the quantity to fall to half of its initial value. ... Willamette Meteorite A meteorite is a natural object originating in outer space that survives an impact with the Earths surface without being destroyed. ... “Rock” redirects here. ... Earth cutaway from core to exosphere. ... World geologic provinces. ... This article is about the chemical element. ... Shocked quartz is a form of quartz that has a microscopic structure that is different from normal quartz. ... Badlands near Drumheller, Alberta where erosion has exposed the KT boundary. ... Orders & Suborders Saurischia Sauropodomorpha Theropoda Ornithischia Thyreophora Ornithopoda Marginocephalia Dinosaurs were vertebrate animals that dominated the terrestrial ecosystem for over 160 million years, first appearing approximately 230 million years ago. ...

Precautions

Osmium tetroxide is highly toxic. Airborne low concentrations of osmium can cause lung congestion, skin or eye damage. Toxic redirects here, but this is also the name of a song by Britney Spears; see Toxic (song) Look up toxic and toxicity in Wiktionary, the free dictionary. ... Human respiratory system The lungs flank the heart and great vessels in the chest cavity. ... Beyond overall skin structure, refer below to: See-also. ... For other uses, see Eye (disambiguation). ...

References

1. ^ H Cynn, J E Klepeis, C S Yeo and D A Young, "Osmium has the Lowest Experimentally-Determined Compressibility", Phys. Rev. Lett. 88 #13 (2002).
2. ^ B R Sahu and L Kleinman, "Osmium Is Not Harder Than Diamond", Phys. Rev. B 72 (2005)
3. ^ http://www.thebulliondesk.com/
4. ^ http://ecplaza.net/ecmarket/list.asp?cmd=search&keywords=osmium+187

External links

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Osmium

Look up osmium in
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• Los Alamos National Laboratory: Osmium
• National Synchrotron Light Source: Science Highlights
• WebElements.com: Osmium

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