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rhodium
rho·di·um R0224200 (rō′dē-əm)n. Symbol Rh A hard, durable, silvery-white metallic element that is used to form high-temperature alloys with platinum and is plated on other metals to produce a durable corrosion-resistant coating. Atomic number 45; atomic weight 102.905; melting point 1,964°C; boiling point 3,695°C; specific gravity 12.41 (20°C); valence 2, 3, 4, 5, 6. See Periodic Table. [Greek rhodo-, rhodo- + -ium.]rhodium (ˈrəʊdɪəm) n (Elements & Compounds) 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[C19: New Latin, from Greek rhodon rose, from the pink colour of its compounds]rho•di•um (ˈroʊ di əm) n. a silvery white metallic element of the platinum family, forming salts that give rose-colored solutions: used to electroplate metals to prevent corrosion. Symbol: Rh; at. wt.: 102.905; at. no.: 45; sp. gr.: 12.5 at 20°C. [1804; < New Latin; see rhodo-, -ium2] rho·di·um (rō′dē-əm) Symbol Rh A rare, silvery-white metallic element that is hard, durable, and resistant to acids. It is used as a permanent plating for jewelry and is added to platinum to make hard alloys that can withstand high temperatures. Atomic number 45. See Periodic Table.ThesaurusNoun | 1. | rhodium - a white hard metallic element that is one of the platinum group and is found in platinum ores; used in alloys with platinumatomic number 45, Rhmetal, metallic element - any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc. | Translations
rhodium
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 ..... Click the link for more information. . 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 ..... Click the link for more information. 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 rhodium
rhodium [ro´de-um] a chemical element, atomic number 45, atomic weight 102.905, symbol Rh. (See Appendix 6.)rho·di·um (Rh), (rō'dē-ŭm), A metallic element, atomic no. 45, atomic wt. 102.90550. [Mod. L. fr. G. rhodon, a rose] rho·di·um (rō'dē-ŭm) A metallic element, atomic no. 45, atomic wt. 102.90550. FinancialSeeRHAcronymsSeeRhrhodium Related to rhodium: Rhodium PlatingSynonyms for rhodiumnoun a white hard metallic element that is one of the platinum group and is found in platinum oresSynonymsRelated Words |