Copper

Copper is a chemical element in the periodic table that has the symbol Cu and atomic number 29.

Physical characteristics

Copper is a reddish-coloured metal, with a high electrical and thermal conductivity (among pure metals at room temperature, only silver has a higher electrical conductivity). Copper has its characteristic color because it reflects red and orange light and absorbs other frequencies in the visible spectrum, due to its band structure.

Related Topics:
Metal - Electrical - Silver - Band structure

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There are two stable isotopes, 63Cu and 65Cu, along with a couple dozen radioisotopes. The vast majority of radioisotopes have half lives on the order of minutes or less, the longest lived, 64Cu, has a half life of 12.7 hours, with two decay modes, leading to two separate products.

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There are numerous alloys of copper - speculum metal is a copper/tin alloy, brass is a copper/zinc alloy, and bronze is a copper/tin alloy. Monel metal is a copper/nickel alloy, also called cupronickel.

Related Topics:
Alloy - Speculum metal - Brass - Zinc - Bronze - Tin - Monel - Nickel - Cupronickel

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Compounds

Common oxidation states of copper include the less stable copper(I) state, Cu+1; and the more stable copper(II) state, Cu+2, which forms lovely blue or blue-green salts. Under unusual conditions, a +3 state can be obtained.

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Copper(II) carbonate is green from which arises the unique appearance of copper-clad roofs or domes on some buildings. Copper(II) sulfate forms a blue crystalline pentahydrate which is perhaps the most familiar copper compound in the laboratory. It is used as a fungicide, known as Bordeau mixture.

Related Topics:
Copper(II) carbonate - Copper(II) sulfate - Hydrate - Fungicide

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There are two stable copper oxides, copper(II) oxide (CuO) and copper(I) oxide (Cu2O). Copper oxides are used to make yttrium barium copper oxide (YBa2Cu3O7-δ) or YBCO which forms the basis of many unconventional superconductors.

Related Topics:
Copper(II) oxide - Copper(I) oxide - Yttrium - Barium - YBCO - Unconventional superconductors

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Other compounds : Copper(I) chloride, copper(II) chloride, copper(II) sulfide.

Related Topics:
Copper(I) chloride - Copper(II) chloride - Copper(II) sulfide

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Occurrence

:See Copper extraction for the main article.

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Copper can be found as native copper in mineral form. Minerals such as the carbonates azurite (Cu3(CO3)2(OH)2) and malachite (Cu2CO3(OH)2) are sources of copper, as are sulfides such as chalcopyrite (CuFeS2), bornite (Cu5FeS4), covellite (CuS), chalcocite (Cu2S) and oxides like cuprite (Cu2O).

Related Topics:
Native copper - Mineral - Carbonate - Azurite - Malachite - Sulfide - Chalcopyrite - Bornite - Covellite - Chalcocite - Cuprite

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Most copper ore is mined or extracted from large open pit mines in copper porphyry deposits that contain 0.4 to 1.0 percent copper. Examples include: Chuquicamata in Chile and El Chino mine in New Mexico.

Related Topics:
Ore - Extracted - Open pit mine - Porphyry - Chuquicamata - Chile - El Chino mine - New Mexico

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The Intergovernmental Council of Copper Exporting Countries (CIPEC), defunct since 1992, once tried to play a similar role for copper as OPEC does for oil, but never achieved the same influence, not least because the second-largest producer, the United States, was never a member. Formed in 1967, its principal members were Chile, Peru, Zaire, and Zambia.

Related Topics:
Intergovernmental Council of Copper Exporting Countries - OPEC - Oil - United States - Chile - Peru - Zaire - Zambia

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