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platinum    音标拼音: [pl'ætnəm] [pl'ætənəm]
n. 白金,铂

白金,铂

platinum
n 1: a heavy precious metallic element; grey-white and resistant
to corroding; occurs in some nickel and copper ores and is
also found native in some deposits [synonym: {platinum}, {Pt},
{atomic number 78}]

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]

platinum
Symbol: Pt
Atomic number: 78
Atomic weight: 195.078
Attractive greyish-white metal. When pure, it is malleable and ductile.
Does not oxidize in air, insoluble in hydrochloric and nitric acid.
Corroded by halogens, cyanides, sulphur and alkalis. {Hydrogen} and
{oxygen} react explosively in the presence of platinum. There are six
stable isotopes and three radioisotopes, the most stable being Pt-193
with a half-life of 60 years. Platinum is used in jewelry, laboratory
equipment, electrical contacts, dentistry, and anti-pollution devices in
cars. PtCl2(NH3)2 is used to treat some forms of cancer.
Platinum-{cobalt}
alloys have magnetic properties. It is also used in the definition of
the Standard Hydrogen Electrode. Discovered by Antonio de Ulloa in South
America in 1735. The name comes from the Spanish word platina which
means
silver. Platinum metal is generally not a health concern due to its
unreactivity, however platinum compounds should be considered highly
toxic.


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  • Platinum - Wikipedia
    Platinum is a chemical element; it has symbol Pt and atomic number 78 It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal Its name originates from Spanish platina, a diminutive of plata "silver" [7][8]
  • Live Platinum Price Charts | Platinum Price Per Ounce - APMEX
    View the current Platinum spot price with APMEX Platinum price charts See the Platinum price per ounce Platinum price per gram to understand your purchasing power
  • Platinum | Color, Symbol, Uses, Facts | Britannica
    Platinum, chemical element, the best known and most widely used of the six platinum metals A very heavy, precious, silver-white metal, platinum is soft and ductile and has a high melting point and good resistance to corrosion and chemical attack Learn more about platinum in this article
  • Platinum Price Today | Price of Platinum Per Ounce | 24 Hour . . .
    Live Platinum Charts and Platinum Spot Price from International Platinum Markets, Prices from New York, London, Hong Kong and Sydney provided by Kitco
  • Platinum: Whats So Special About the Shiny Metal?
    Platinum is coveted for its rarity, resilience and versatility Its scarcity makes the noble metal exclusive and valuable, while its resistance to corrosion and ability to withstand extreme conditions make it ideal for various industries
  • Platinum : Properties, Uses, Occurrence and Localities . . .
    Platinum is a precious metal that is known for its rarity, beauty, and various industrial applications It is a chemical element with the symbol Pt and atomic number 78 on the periodic table
  • Platinum | History, Uses, Facts, Physical Chemical . . .
    Platinum is a chemically stable element as it is one of the least reactive metals (Nobel metal) platinum have two oxidation states, +2 and +4 Platinum readily reacts with carbon Certain non-metals, including phosphorus, silicon and sulfur also combine with platinum





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