AskDefine | Define metals

User Contributed Dictionary

English

Noun

metals
  1. Plural of metal
  2. the rail tracks owned by a company or organisation; a rail network
    It was appropriate that 'King' number 6000 began the return to steam on British Rail metals in 1971.

Extensive Definition

In chemistry, a metal (Greek: Metallon) is defined as an element that readily loses electrons to form positive ions (cations) and forms metallic bonds between other metal atoms (forming ionic bonds with non-metals).
Metals are good conductors, making them valuable in electrical appliances and for carrying an electric current over a distance with little energy lost. Electrical power grids rely on metal cables to distribute electricity. Home electrical systems, for the most part, are wired with copper wire for its good conducting properties.
The thermal conductivity of metal is useful for containers to heat materials over a flame. Metal is also used for heat sinks to protect sensitive equipment from overheating.
The high reflectivity of some metals is important in the construction of mirrors, including precision astronomical instruments. This last property can also make metallic jewelry aesthetically appealing.
Some metals have specialized uses; Radioactive metals such as Uranium and Plutonium are used in nuclear power plants to produce energy via nuclear fission. Mercury is a liquid at room temperature and is used in switches to complete a circuit when it flows over the switch contacts. Shape memory alloy is used for applications such as pipes, fasteners and vascular stents. However they are very good at conducting electricity and heat.

Trade

The World Bank reports that China was the top importer of ores and metals in 2005 followed by the U.S.A. and Japan.

Astronomy

In the specialised usage of astronomy and astrophysics, the term "metal" is often used to refer to any element other than hydrogen or helium, including substances as chemically non-metallic as neon, fluorine, and oxygen. Nearly all the hydrogen and helium in the Universe was created in Big Bang nucleosynthesis, whereas all the "metals" were produced by nucleosynthesis in stars or supernovae. The Sun and the Milky Way Galaxy are composed of roughly 70% hydrogen, 30% helium, and 2% "metals" by mass.
metallic elements
metals in Arabic: فلز
metals in Bosnian: Metal (hemija)
metals in Bulgarian: Метал
metals in Catalan: Metall
metals in Czech: Kov
metals in Welsh: Metel
metals in Danish: Metal
metals in German: Metalle
metals in Estonian: Metallid
metals in Modern Greek (1453-): Μέταλλα
metals in Spanish: Metal
metals in Esperanto: Metalo (fiziko)
metals in Persian: فلز
metals in French: Métal
metals in Scottish Gaelic: Meatailt
metals in Korean: 금속
metals in Hindi: धातु
metals in Croatian: Kovine
metals in Indonesian: Logam
metals in Interlingua (International Auxiliary Language Association): Metallo
metals in Icelandic: Málmur
metals in Italian: Metallo
metals in Hebrew: מתכת
metals in Kurdish: Lajwerd
metals in Latin: Metallum
metals in Latvian: Metāls
metals in Luxembourgish: Metall
metals in Lithuanian: Metalai
metals in Lojban: jinme
metals in Lombard: Metàj
metals in Hungarian: Fémek
metals in Macedonian: Метал
metals in Malayalam: ലോഹം
metals in Malay (macrolanguage): Logam
metals in Mongolian: Металл
metals in Dutch: Metaal
metals in Japanese: 金属
metals in Norwegian: Metall
metals in Norwegian Nynorsk: Metall
metals in Narom: Méta
metals in Low German: Metall
metals in Polish: Metale (chemia)
metals in Portuguese: Metal
metals in Romanian: Metal
metals in Quechua: Q'illay
metals in Russian: Металлы
metals in Simple English: Metal
metals in Slovak: Kov
metals in Slovenian: Kovina
metals in Serbian: Метал (хемија)
metals in Serbo-Croatian: Metal (hemija)
metals in Finnish: Metalli
metals in Swedish: Metall
metals in Tagalog: Metal
metals in Tamil: உலோகம்
metals in Thai: โลหะ
metals in Vietnamese: Kim loại
metals in Cherokee: ᎠᎾᎦᎵᏍᎩ ᎦᏂᏱᏍᎩ
metals in Turkish: Metal (kimya)
metals in Ukrainian: Метали
metals in Yiddish: מעטאל
metals in Contenese: 金屬
metals in Chinese: 金属
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