transition metal

The appearance of this element is unknown, however it is most likely silvery-white or gray and metallic. If sufficient amounts of lawrencium were produced, it would pose a radiation hazard. Very little is known about the chemical properties of this element but some preliminary work on a few atoms has indicated that it behaves similarly to the actinides. Element 103 is a d-block element analogous to lutetium and therefore is increasingly being placed with the other d-block elements in the transition metal chemical series, but it is still most o ...

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Lawrencium, Lawrencium - Notable characteristics, Lawrencium - History

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Silver is a very ductile and malleable (slightly harder than gold) univalent coinage metal with a brilliant white metallic luster that can take a high degree of polish. It has the highest electrical conductivity of all metals, even higher than copper, but its greater cost has prevented it from being widely used in place of copper for electrical purposes. Pure silver also has the highest thermal conductivity, whitest colour, the highest optical reflectivity (although it is a poor reflector of ultraviolet), and the lowest contact resist ...

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Silver, Silver - Notable characteristics, Silver - Applications, Silver - History, Silver - Occurrence, Silver - Isotopes, Silver - Precautions and health effects

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Naturally occurring cadmium is composed of 8 isotopes. For two of them, natural radioactivity was observed, and other three are predicted to be radioactive but their decays were never observed, due to extremely long half-life times. The two natural radioactive isotopes are 113Cd (beta decay, half-life is 7.7 X 1015 years) and 116Cd (two-neutrino double beta decay, half-life is 2.9 X 1019 years). Other three ones are 106Cd, 108Cd (double electron capture), and 114Cd ...

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Cadmium, Cadmium - Notable characteristics, Cadmium - Applications, Cadmium - History, Cadmium - Occurrence, Cadmium - Isotopes, Cadmium - Precautions

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In these hydrodesulfurization processes the liquid is treated with hydrogen gas using a molybdenum disulfide catylist which is oftein promoted with cobalt. In this process the thiophenes are reduced to form hydrocarbons and hydrogen sulfide, the most easy to process thiophenes are simple thiophenes, and the hardest thiophenes to treat are the dibenzothiopehenes. The ease of hydrodesulfurization of the benzothiopehenes is midway betwe ...

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Hydrodesulfurization, Hydrodesulfurization - Process, Hydrodesulfurization - catylist, Hydrodesulfurization - Mechanism

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Naturally occurring ruthenium is composed of seven isotopes. The most stable radioisotopes are Ru-106 with a half-life of 373.59 days, Ru-103 with a half-life of 39.26 days and Ru-97 with a half-life of 2.9 days. Fifteen other radioisotopes have been characterized with atomic weights ranging from 89.93 amu (Ru-90) to 114.928 (Ru-115). Most of these have half-lifes that are less than five minutes except Ru-95 (half-life: 1.643 ...

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Ruthenium, Ruthenium - Notable characteristics, Ruthenium - Applications, Ruthenium - History, Ruthenium - Occurrence, Ruthenium - Compounds, Ruthenium - Isotopes, Ruthenium - Organometallic chemistry, Ruthenium - Precautions

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It is quite easy to form compounds with carbon ruthenium bonds, these compounds tend to be darker and react more quickly than the osmium compounds. Recently Prof Tony Hill and his co-workers have been making compounds of ruthenium in which a boron atom binds to the metal atom. The organometallic ruthenium compound that is easiest to make is RuHCl(CO)(PPh3)3. This compound has two forms (yellow and pink) that are identical onc ...

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Ruthenium, Ruthenium - Notable characteristics, Ruthenium - Applications, Ruthenium - History, Ruthenium - Occurrence, Ruthenium - Compounds, Ruthenium - Isotopes, Ruthenium - Organometallic chemistry, Ruthenium - Precautions

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Mercury is used primarily for the manufacture of industrial chemicals or for electrical and electronic applications. It is used in some thermometers, especially ones which are used to measure high temperatures (In the United States, non-prescription sale of mercury fever thermometers was banned by a number of different states and localities). Other uses: Mercury sphygmomanometers. Thimerosal, an organic compound used as a preservative in vaccines and tattoo inks (Thimerosal in vaccines). Mercury barometers, dif ...

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Mercury element, Mercury element - Applications, Mercury element - History, Mercury element - Dentistry, Mercury element - Medicine, Mercury element - Mineral occurrence, Mercury element - Compounds, Mercury element - Isotopes, Mercury element - Occurrence in the environment, Mercury element - Health and Environmental Effects, Mercury element - Precautions and regulation, Mercury element - Occupational exposure, Mercury element - Mercury in fish, Mercury element - Release of mercury into the environment, Mercury element - Mercury and aluminum

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The most important salts are: Mercury(I) chloride (AKA calomel) is sometimes still used in medicine and acousto-optical filters Mercury(II) chloride (which is very corrosive, sublimates and is a violent poison) Mercury fulminate, (a detonator widely used in explosives), Mercury(II) sulfide (AKA cinnabar mercuric ore still used in oriental medicine, or vermilion which is a high-grade paint pigment), Mercury(II) selenide a semi-metal, Mercury(II) telluride a semi-metal, and Mercury cadmium telluride and mercury zinc t ...

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Mercury element, Mercury element - Applications, Mercury element - History, Mercury element - Dentistry, Mercury element - Medicine, Mercury element - Mineral occurrence, Mercury element - Compounds, Mercury element - Isotopes, Mercury element - Occurrence in the environment, Mercury element - Health and Environmental Effects, Mercury element - Precautions and regulation, Mercury element - Occupational exposure, Mercury element - Mercury in fish, Mercury element - Release of mercury into the environment, Mercury element - Mercury and aluminum

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Electron spin resonance - The g factor. Knowledge of the g factor gives us information about the paramagnetic center's electronic structure. When an unpaired electron is in an atom, it feels not only the external magnetic field B0 applied by the spectrometer, but also the effects of any local magnetic fields. Therefore, the effective field Beff felt by the electron is Beff = B0(1 - σ) where σ allows for the effects of the local fields (it can ...

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Electron spin resonance, Electron spin resonance - EPR theory, Electron spin resonance - Units and constants, Electron spin resonance - Basics, Electron spin resonance - Boltzmann distribution, Electron spin resonance - EPR spectral parameters, Electron spin resonance - The g factor, Electron spin resonance - Resonance linewidth definition

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Technical Ceramics can also be classified into three distinct material categories: Oxides: Alumina, zirconia Non-oxides: Carbides, borides, nitrides, silicides Composites: Particulate reinforced, combinations of oxides and non-oxides. Each one of these classes can develop unique material properties Ceramics - Examples of ceramic materials. Barium strontium calcium copper oxide, a high-temperature superconductor Barium titanate (often mixed with st ...

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Ceramics, Ceramics - Classifications of technical ceramics, Ceramics - Examples of ceramic materials, Ceramics - Properties of ceramics, Ceramics - Mechanical properties, Ceramics - Electrical properties, Ceramics - Processing of ceramic materials, Ceramics - In situ manufacturing, Ceramics - Sintering-based methods, Ceramics - Other applications of ceramics

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Ruthenium (Latin Ruthenia meaning "Russia") was discovered and isolated by Karl Klaus in 1844. Klaus showed that ruthenium oxide contained a new metal and obtained 6 grams of ruthenium from the part of crude platinum that is insoluble in aqua regia. Jöns Berzelius and Gottfried Osann nearly discovered ruthenium in 1827. The men examined residues that were left after dissolving crude platinum from the Ural Mountains in aqua regia. Berzelius did not find any unusual metals, but Osann thought he found three new me ...

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Ruthenium, Ruthenium - Notable characteristics, Ruthenium - Applications, Ruthenium - History, Ruthenium - Occurrence, Ruthenium - Compounds, Ruthenium - Isotopes, Ruthenium - Organometallic chemistry, Ruthenium - Precautions

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Because of its many uses, ammonia is one of the most highly-produced inorganic chemicals. Before the start of WWI most ammonia was obtained by the dry distillation of nitrogenous vegetable and animal products; by the reduction of nitrous acid and nitrites with nascent hydrogen; and also by the decomposition of ammonium salts by alkaline hydroxides or by quicklime, the salt most generally used being the chloride (sal-ammoniac) thus 2NH4Cl + 2CaO → CaCl2 + Ca(OH)2See also:

Ammonia, Ammonia - History, Ammonia - Production, Ammonia - Properties, Ammonia - Formation of salts, Ammonia - Acidity, Ammonia - Formation of other compounds, Ammonia - Ammonia as a ligand, Ammonia - Uses, Ammonia - Liquid ammonia as a solvent, Ammonia - Solubility of salts, Ammonia - Solutions of metals, Ammonia - Redox properties of liquid ammonia, Ammonia - Detection and determination, Ammonia - Safety precautions, Ammonia - Toxicity, Ammonia - Household use, Ammonia - Laboratory use of ammonia solutions, Ammonia - Laboratory use of anhydrous ammonia gas or liquid, Ammonia - Reference, Ammonia - Bibliography

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Rhodium (Greek rhodon meaning "rose") was discovered in 1803 by William Hyde Wollaston soon after his discovery of palladium. Wollaston made this discovery in England using crude platinum ore that he presumably obtained from South America. His procedure involved dissolving the ore in aqua regia, neutralizing the acid with sodium hydroxide (NaOH). He then precipitated the platinum metal by adding ammonium chloride, NH4Cl, as ammonium chloroplatinate. The element palladium was removed as palladium cyanide after treatin ...

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Rhodium, Rhodium - Notable characteristics, Rhodium - Applications, Rhodium - History, Rhodium - Occurrence, Rhodium - Isotopes, Rhodium - Precautions

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Natural tantalum consists of two isotopes. Ta-181 is a stable isotope, and Ta-180m, which has a half life of over 1015 years (see scientific notation) and is a nuclear isomer of Ta-180. Ta-180 has a ground state half life of only 8 hours. Tantalum has been proposed as a "salting" material for nuclear weapons. (Cobalt is another, better-known salting material.) A jacket of natural tantalum, irradiated by the intense high-energy neutron flux from an exploding thermonuclear weapon, would transmute into the radioactive isotope ...

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Tantalum, Tantalum - Notable characteristics, Tantalum - Applications, Tantalum - History, Tantalum - Occurrence, Tantalum - Compounds, Tantalum - Isotopes, Tantalum - Precautions

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Tantalum occurs principally in the mineral tantalite [(Fe, Mn) Ta2O6] and euxenite (other minerals: samarskite, and fergusonite). Tantalum ores are mined in Australia, Brazil, Egypt, Canada, the Democratic Republic of the Congo, Mozambique, Nigeria, Portugal, Malaysia and Thailand. A comprehensive, 2002 picture of non-Australian mines is reasonably current. Tantalite is largely found mixed with columbite in an ore called coltan. Ethical questions have been raised about human rights and endangered wildlife, due to the exploitation of resources in the conf ...

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Tantalum, Tantalum - Notable characteristics, Tantalum - Applications, Tantalum - History, Tantalum - Occurrence, Tantalum - Compounds, Tantalum - Isotopes, Tantalum - Precautions

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Tantalum (Greek Tantalus, mythological character) was discovered in Sweden in 1802 by Anders Ekeberg and isolated in 1820 by Jöns Berzelius. Many contemporary chemists believed niobium and tantalum were the same elements until 1844 and later 1866 when researchers showed that niobic and tantalic acids were different compounds. Early investigators were only able to isolate impure metal and the first relatively pure ductile metal was produced by Werner von Bolton in 1903. Wires made with tantalum metal were used for lig ...

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Tantalum, Tantalum - Notable characteristics, Tantalum - Applications, Tantalum - History, Tantalum - Occurrence, Tantalum - Compounds, Tantalum - Isotopes, Tantalum - Precautions

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Salts of ammonia have been known from very early times; thus the term Hammoniacus sal appears in the writings of Pliny, although it is not known whether the term is identical with the more modern sal-ammoniac. In the form of sal-ammoniac, ammonia was known to the alchemists as early as the 13th century, being mentioned by Albertus Magnus. It was also used by dyers in the Middle Ages in the form of fermented urine to alter the colour of vegetable dyes. In the 15th century, Basilius Valentinus showed that ammonia could be ...

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Ammonia, Ammonia - History, Ammonia - Production, Ammonia - Properties, Ammonia - Formation of salts, Ammonia - Acidity, Ammonia - Formation of other compounds, Ammonia - Ammonia as a ligand, Ammonia - Uses, Ammonia - Liquid ammonia as a solvent, Ammonia - Solubility of salts, Ammonia - Solutions of metals, Ammonia - Redox properties of liquid ammonia, Ammonia - Detection and determination, Ammonia - Safety precautions, Ammonia - Toxicity, Ammonia - Household use, Ammonia - Laboratory use of ammonia solutions, Ammonia - Laboratory use of anhydrous ammonia gas or liquid, Ammonia - Reference, Ammonia - Bibliography

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Naturally occurring rhodium is composed of only one isotope (Rh-103). The most stable radioisotopes are Rh-101 with a half-life of 3.3 years, Rh-102m with a half-life of 207 days, Rh-102 with a half-life of 2.9 years, and Rh-99 with a half-life of 16.1 days. Twenty other radioisotopes have been characterized with atomic weights ranging from 92.926 u (Rh-93) to 116.925 u (Rh-117). Most of these have half-lifes that are less than an hour except Rh-100 (half-life: 20.8 hours) and Rh-105 (half-life: 35.36 hours). There are also numerous meta states with the most stable being Rhm-102 (0.141 MeV) with a half-life of about 207 days and Rhm-101 (0.157 ...

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Rhodium, Rhodium - Notable characteristics, Rhodium - Applications, Rhodium - History, Rhodium - Occurrence, Rhodium - Isotopes, Rhodium - Precautions

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Abundance Crustal ~7×10-2 mg/kg Oceans ~3×10-5 mg/L Preindustrial deposition rates of mercury from the atmosphere may be in the range of 4 ng/L in the western USA. Although that can be considered a natural level of exposure, regional or global sources have significant effects. Volcanic eruptions can increase the atmospheric source by 4–6 times. [3] Mercury enters the environment as a pollutant from various industries: coal-fired power plants are the largest sou ...

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Mercury element, Mercury element - Applications, Mercury element - History, Mercury element - Dentistry, Mercury element - Medicine, Mercury element - Mineral occurrence, Mercury element - Compounds, Mercury element - Isotopes, Mercury element - Occurrence in the environment, Mercury element - Health and Environmental Effects, Mercury element - Precautions and regulation, Mercury element - Occupational exposure, Mercury element - Mercury in fish, Mercury element - Release of mercury into the environment, Mercury element - Mercury and aluminum

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Due to its highly effective ability to harden platinum and palladium, ruthenium is used in Pt and Pd alloys to make severe wear resistance electrical contacts. 0.1% ruthenium is added to titanium to improve its corrosion resistance a hundredfold. Ruthenium is also a versatile catalyst: Hydrogen sulfide can be split by light by using an aqueous suspension of CdS particles loaded with ruthenium dioxide. This may be useful in the removal of H2S from oil refin ...

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Ruthenium, Ruthenium - Notable characteristics, Ruthenium - Applications, Ruthenium - History, Ruthenium - Occurrence, Ruthenium - Compounds, Ruthenium - Isotopes, Ruthenium - Organometallic chemistry, Ruthenium - Precautions

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Non-crystalline ceramics, being glasses, tend to be formed from melts. The glass is shaped when either fully molten, by casting, or when in a state of toffee-like viscosity, by methods such as blowing to a mould. If later heat-treatments cause this class to become partly crystalline, the resulting material is known as a glass-ceramic. Crystalline ceramic materials are not amenable to a great range of processing. Methods for dealing with them tend to fall into one of two categories - either make the ceramic in the desired shape, by rea ...

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Ceramics, Ceramics - Classifications of technical ceramics, Ceramics - Examples of ceramic materials, Ceramics - Properties of ceramics, Ceramics - Mechanical properties, Ceramics - Electrical properties, Ceramics - Processing of ceramic materials, Ceramics - In situ manufacturing, Ceramics - Sintering-based methods, Ceramics - Other applications of ceramics

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A couple of decades ago, Toyota researched production of an adiabatic ceramic engine which can run at a temperature of over 6000 °F (3300 °C). Ceramic engines do not require a cooling system and hence allow a major weight reduction and therefore greater fuel efficiency. Fuel efficiency of the engine is also higher at high temperature. In a conventional metallic engine, much of the energy released from the fuel must be dissipated as waste ...

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Ceramics, Ceramics - Classifications of technical ceramics, Ceramics - Examples of ceramic materials, Ceramics - Properties of ceramics, Ceramics - Mechanical properties, Ceramics - Electrical properties, Ceramics - Processing of ceramic materials, Ceramics - In situ manufacturing, Ceramics - Sintering-based methods, Ceramics - Other applications of ceramics

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