rhodium


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rhodium

(rō`dēəm), metallic chemical element; symbol Rh; at. no. 45; at. wt. 102.90550; m.p. about 1,966°C;; b.p. 3,727±100°C;; sp. gr. 12.41 at 20°C;; valence +2, +3, +4, +5, or +6. Rhodium is a lustrous, silver-white, chemically resistant metal in the so-called platinum group of metals in Group 9 of the periodic tableperiodic table,
chart of the elements arranged according to the periodic law discovered by Dmitri I. Mendeleev and revised by Henry G. J. Moseley. In the periodic table the elements are arranged in columns and rows according to increasing atomic number (see the table entitled
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. It has a face-centered cubic crystalline structure. It is insoluble in most acids, including aqua regia, but is dissolved in hot concentrated sulfuric acid. Rhodium compounds include halides, oxides, sulfates, sulfites, a nitrate, and a sulfide. The salts form rose-colored aqueous solutions. Rhodium is found associated with other platinum metals in river sands and in compounds in such minerals as rhodite and sperrylite. It is obtained as a byproduct in the refining of nickel sulfide ores mined near Sudbury, Ont., Canada.

The major use of the metal is in alloys with platinum and iridium; it gives improved high-temperature strength and oxidation resistance. These alloys are used in pen nibs, high-temperature thermocouple and resistance wires, bearings, and electrical contacts and as a catalyst. In motor vehicle catalytic converters, it converts the nitrogen oxides in the exhaust into nitrogen and oxygen. The metal itself, because of its brilliance and resistance to tarnish, is used to plate jewelry and the reflectors of searchlights. Rhodium was discovered in 1804 by W. H. WollastonWollaston, William Hyde,
1766–1828, English scientist, M.D. Cambridge, 1793. His wide-ranging scientific achievements include the discovery (1802) of the dark lines (Fraunhofer lines) in the solar spectrum; invention of the reflecting goniometer (an instrument by which the
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 in crude platinum ore.

rhodium

[′rōd·ē·əm]
(chemistry)
A chemical element, symbol Rh, atomic number 45, atomic weight 102.9055.
(metallurgy)
A silver-white metal in the platinum family; sometimes alloyed with platinum for thermocouples or used as a tarnish-resistant electrode posit.

rhodium

a hard corrosion-resistant silvery-white element of the platinum metal group, occurring free with other platinum metals in alluvial deposits and in nickel ores. It is used as an alloying agent to harden platinum and palladium. Symbol: Rh; atomic no.: 45; atomic wt.: 102.90550; valency: 2--6; relative density: 12.41; melting pt.: 1963?3?C; boiling pt.: 3697?100?C
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While there are a few exchange-traded funds backed by rhodium, they are small and thinly traded.
In summary, we report herein the synthesis and characterization of four paddlewheel rhodium complexes, 1-4, assisted by microwave irradiation under laboratory atmosphere in quantitative yields.
Thus it is unequivocally established that for rhodium the secant, tangent and the virtual axis for an adjacent hyperbola are represented by just one line, providing for the first time a means to the necessary geometrical constructions on the basis of only its atomic mass (the only one in the Periodic Table), for the proof of the Hyperbolic Law.
At reduction of rate of melting below 4.5 kg/h total percent of metal yield into ingot gets lower, because main evaporating components (platinum and rhodium) partially transit into the condensate.
In addition, a further expansion in glassmaking capacity in the Far East should also require more platinum and rhodium for furnaces and related equipment.
Eventually, the team found the answer in rhodium. "This has been a major breakthrough for us," Brewer says.
Platexco says that it is satisfied that there are reserves amounting to 11.1 m/oz of platinum group metals at an average head grade of 5.54g/t (platinum, palladium, rhodium and gold).
Singapore: Fitch Ratings has assigned Singapore-based commodity trader Rhodium Resources Pte.
Lee, an X-ray scientist at Argonne, said in (http://www.anl.gov/articles/making-fuel-out-thick-air) a statement Thursday: "Our work shows the potential of rhodium to enable this conversion under 'mild conditions' such as lower temperatures.
24 August 2017 - In a joint venture partnership with New York, US-based real estate developer Rhodium Capital Advisors LLC, an affiliate of Canada-based private equity company Firm Capital has acquired a portfolio of 14 Connecticut, US-based multi-family properties for USD 30.5m, the company said.