platinum


1plat·i·num

noun, often attributive \ˈplat-nəm, ˈpla-tə-nəm\

: a heavy, silver-colored metal that is difficult to melt and that is used especially in expensive jewelry

Full Definition of PLATINUM

1
:  a precious grayish-white noncorroding ductile malleable heavy metallic element that fuses with difficulty and is used especially in chemical ware and apparatus, as a catalyst, and in dental and jewelry alloys — see element table
2
:  a moderate gray

Origin of PLATINUM

New Latin, from Spanish platina, from diminutive of plata silver — more at plate
First Known Use: 1808

2platinum

adjective

Definition of PLATINUM

:  qualifying for a platinum record
go platinum
:  to have enough sales to qualify for a platinum record

First Known Use of PLATINUM

1971

plat·i·num

noun \ˈplat-nəm, -ən-əm\   (Medical Dictionary)

Medical Definition of PLATINUM

: a heavy precious grayish white noncorroding ductile malleable metallic element that fuses with difficulty and is used especially in chemical ware and apparatus, as a catalyst, and in dental and jewelry alloys—symbol Pt; see element table

platinum

noun    (Concise Encyclopedia)

Metallic chemical element, one of the transition elements, chemical symbol Pt, atomic number 78. A very heavy, silvery white precious metal, it is soft and ductile, with a high melting point (3,216 °F [1,769 °C]) and good resistance to corrosion and chemical attack. Small amounts of iridium are commonly added for a harder, stronger alloy that retains platinum's advantages. Platinum is found usually as alloys of 80–90% purity in placer deposits or more rarely combined with arsenic or sulfur. It is indispensable in high-temperature laboratory work for electrodes, dishes, and electrical contacts that resist chemical attack even when very hot. Platinum is used in dental alloys and surgical pins; alloys typically containing 90–95% platinum are used in expensive jewelry. The international primary standard for the kilogram is made of 90% platinum, 10% iridium. Platinum has valence 2 or 4 in its compounds, which include many coordination complexes. It and some compounds are useful catalysts, particularly for hydrogenation and in catalytic converters for reducing automobile emissions.

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