Platinum Plat"i*num, n. [NL., fr. Sp. platina, from plata silver, LL. plata a thin plate of metal. See {Plate}, and cf. {Platina}.] (Chem.) A metallic element of atomic number 78, one of the noble metals, classed with silver and gold as a precious metal, occurring native or alloyed with other metals and also as the platinum arsenide (sperrylite). It is a heavy tin-white metal which is ductile and malleable, but very infusible (melting point 1772[deg] C), and characterized by its resistance to strong chemical reagents. It is used for crucibles in laboratory operations, as a catalyst, in jewelry, for stills for sulphuric acid, rarely for coin, and in the form of foil and wire for many purposes. Specific gravity 21.5. Atomic weight 195.1. Symbol Pt. Formerly called {platina}. [1913 Webster +PJC]

{Platinum black} (Chem.), a soft, dull black powder, consisting of finely divided metallic platinum obtained by reduction and precipitation from its solutions. It absorbs oxygen to a high degree, and is employed as an oxidizer.

{Platinum lamp} (Elec.), a kind of incandescent lamp of which the luminous medium is platinum. See under {Incandescent}.

{Platinum metals} (Chem.), the group of metallic elements which in their chemical and physical properties resemble platinum. These consist of the light platinum group, viz., rhodium, ruthenium, and palladium, whose specific gravities are about 12; and the heavy platinum group, viz., osmium, iridium, and platinum, whose specific gravities are over 21.

{Platinum sponge} (Chem.), metallic platinum in a gray, porous, spongy form, obtained by reducing the double chloride of platinum and ammonium. It absorbs oxygen, hydrogen, and certain other gases, to a high degree, and is employed as an agent in oxidizing. [1913 Webster]

The Collaborative International Dictionary of English. 2000.


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  • Platina —     Bartolomeo Platina     † Catholic Encyclopedia ► Bartolomeo Platina     Originally named SACCHI, b. at Piadena, near Mantua, in 1421; d. at Rome, 1481. He first enlisted as a soldier, and was then appointed tutor to the sons of the Marquis… …   Catholic encyclopedia

  • Platina — und Papst Sixtus IV., Fresko von Melozzo da Forlì Bartolomeo Platina (eigentl. Bartolomeo Sacchi, * 1421 in Piadena, lat. Platina, bei Cremona, Lombardei; † 21. September 1481 in Rom) war ein italienischer Humanist und Bibliothekar. Plat …   Deutsch Wikipedia

  • platina — PLATINÁ, platinez, vb. I. tranz. 1. A acoperi un obiect de metal cu un strat subţire de platină (1); a sufla cu platină. 2. A decolora părul capului prin mijloace chimice, dându i o nuanţă de blond argintiu. – Din fr. platiner. Trimis de… …   Dicționar Român

  • platină — PLÁTINĂ, (2, 3) platine, s.f. 1. Metal preţios de culoare albă cenuşie, dur, lucios, inoxidabil, foarte maleabil şi ductil, foarte rezistent la căldură şi la acţiunea acizilor, folosit la fabricarea unor aparate de laborator, a unor instrumente… …   Dicționar Român

  • Platina — Saltar a navegación, búsqueda Platina puede referirse a: Platina: Base plana, de vidrio, donde se ponen las preparaciones para su observación en el microscopio. Con el ajuste macrométrico se puede subir y bajarlo hasta aconseguir un enfoque… …   Wikipedia Español

  • Platina — Administration Pays  Brésil …   Wikipédia en Français

  • Platina — Plat i*na, n. [Sp. or NL. See {Platinum}.] (Chem.) Platinum. [1913 Webster] {Platina mohr}, platinum black. {Platina yellow}, a pigment prepared from platinum. [1913 Webster] …   The Collaborative International Dictionary of English

  • platina — s. f. 1.  [Química] Elemento químico metálico precioso (símbolo Pt), de número atômico 78, de massa atômica 195,09, de um branco acinzentado. 2. Presilha ou pestana que os soldados têm no ombro do casaco ou jaleco para segurar as correias.… …   Dicionário da Língua Portuguesa

  • platina — platinà sf. sing. (2) TrpŽ, plãtina (1) BŽ368, plãtyna (1) KII111 chem. brangusis plieninio atspalvio, labai tampus ir kietas metalas (Pt): Pati tankiausia medžiaga Žemės paviršiuje yra platina rš …   Dictionary of the Lithuanian Language

  • Platina — is a municipality (município) in the state of São Paulo in Brazil. The population in 2004 is 2,866 and the area is 328.68 km². The elevation is 466 m …   Wikipedia

  • Platīna — Platīna, s. Platin. Auch soviel wie Weißmessing, s. Messing, S. 666 …   Meyers Großes Konversations-Lexikon

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