Information AboutCopper |
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| color2=black }} | color2=black }} | color2=black }} | color2=black }} | color2=black }} Copper is a 29. It is a Ductile Metal with excellent Electrical Conductivity , and finds extensive use as an electrical conductor, as a building material, and as a component of various Alloy s. Notable characteristics Copper is a reddish-colored 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 . Contrast this with the optical properties of Silver , Gold and Aluminium . Copper occupies the same family of the periodic table as silver and gold, hence it shares many characteristics with these metals. All have high thermal and electrical conductivity. All are malleable metals. Gold and copper are the only colored metallic elements. Copper is insoluble in water (H2O) as well as in isopropanol, or isopropyl alcohol. There are two stable isotopes, 63Cu and 65Cu, along with a couple of 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. There are numerous Alloy s 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 . While the metal "bronze" usually refers to copper/tin alloys, it also is a generic term for any alloy of copper, such as aluminum bronze, silicon bronze, and manganese bronze. Applications Copper is Malleable and Ductile , and is used extensively, in products such as:
]] History In Greek times, the metal was known by the name ''chalkos'' (χαλκός). Copper was a very important resource for the Romans and Greeks. In Roman times, it became known as ''aes Cyprium'' (''aes'' being the generic Latin term for copper alloys such as Bronze and other metals, and ''Cyprium'' because so much of it was mined in Cyprus ). From this, the phrase was simplified to ''cuprum'' and then eventually Anglicized into the English ''copper''. Copper was associated with the goddess Aphrodite / Venus in mythology and Alchemy , owing to its lustrous beauty, its ancient use in producing mirrors, and its association with Cyprus , which was sacred to the goddess. In Alchemy the symbol for copper was also the symbol for the planet Venus . from Zakros , Crete is shaped in the form of an animal skin typical for that era.]]Copper was known to some of the oldest civilizations on record, and has a history of use that is at least 10,000 years old. A copper pendant was found in what is now northern Iraq that dates to 8700 BC. By 5000 BC, there are signs of copper Smelting , the refining of copper from simple copper oxides such as Malachite or Azurite . The earliest signs of Gold use, by contrast, appear around 4000 BC. There are copper and Bronze artifacts from Sumer ian cities that date to 3000 BC, and Egyptian artifacts in copper and copper alloyed with Tin nearly as old. In one pyramid, a copper plumbing system was found that is 5000 years old. The Egyptians found that adding a small amount of tin made the metal easier to cast, so bronze alloys were found in Egypt almost as soon as copper was found. Use of copper in ancient China dates to at least 2000 BC. By 1200 BC excellent bronzes were being made in China. Note that these dates are affected by wars and conquest, as copper is easily melted down and reused. In Europe, Oetzi The Iceman , a well-preserved male dated to 3200 BC , was found with a copper-tipped axe whose metal was 99.7% pure. High levels of Arsenic in his hair suggests he was involved in copper smelting. Brass , an Alloy of Zinc and copper, was known to the Greek s but first used extensively by the Romans . The use of Bronze was so pervasive in a certain era of civilization that it has been named the Bronze Age . The transitional period in certain regions between the preceding Neolithic period and the Bronze Age is termed the Chalcolithic , with some high-purity copper tools being used alongside stone tools. Historical copper mining in Copper Country , Michigan, USA in 1905.]] Copper has been mined for many centuries. By 2000 BC, Europe was using copper-tin alloys or ‘bronze’. The Bronze Age is taken as 2500 BC to 600 BC. During the Bronze age, copper was mined in the British Isles mainly in the following locations:
At Great Orme in North Wales, such working extended for a depth of 70 metres (ref: O’Brien, W., Bronze Age Copper Mining in Britain and Ireland) At Alderley Edge in Cheshire , carbon dates have established mining at around 2280 - 1890 BC (at 95% probability) (ref: Timberlake and Prag, 2005). Biological role Copper is essential in all higher plants and animals. Copper is carried mostly in the bloodstream on a Plasma Protein called Ceruloplasmin . When copper is first absorbed in the gut it is transported to the Liver bound to Albumin . Copper is found in a variety of Enzyme s, including the copper centers of Cytochrome C Oxidase and the enzyme Superoxide Dismutase (containing copper and zinc). In addition to its enzymatic roles, copper is used for biological electron transport. The blue copper proteins that participate in electron transport include azurin and Plastocyanin . The name "blue copper" comes from their intense blue color arising from a ligand-to-metal charge transfer (LMCT) absorption band around 600 nm. Most Mollusc s and some Arthropod s such as the Horseshoe Crab use the copper-containing pigment Hemocyanin rather than Iron -containing Hemoglobin for oxygen transport, so their blood is blue when oxygenated rather than red. It is believed that Zinc and copper compete for absorption in the digestive tract so that a diet that is excessive in one of these minerals may result in a deficiency in the other. The RDA for copper in normal healthy adults is 0.9 Mg /day. Toxicity All copper compounds, unless otherwise known, should be treated as if they were Toxic . Thirty grams of copper sulfate is potentially lethal in humans. The suggested safe level of copper in Drinking Water for humans varies depending on the source, but tends to be pegged at 1.5 to 2 mg/L. The DRI Tolerable Upper Intake Level for adults of dietary copper from all sources is 10 mg/day. In toxicity, copper can inhibit the Enzyme Dihydrophil Hydratase , an enzyme involved in Haemopoiesis . A significant portion of the toxicity of copper comes from its ability to accept and donate single electrons as it changes oxidation state. This catalyzes the production of very reactive radical ions such as Hydroxyl Radical in a manner similar to Fenton Chemistry . This catalytic activity of copper is used by the enzymes that it is associated with and is thus only toxic when unsequestered and unmediated. This increase in unmediated reactive radicals is generally termed Oxidative Stress and is an active area of research in a variety of diseases where copper may play an important but more subtle role than in acute toxicity. An inherited condition called Wilson's Disease causes the body to retain copper, since it is not excreted by the Liver into the Bile . This disease, if untreated, can lead to Brain and Liver damage. In addition, studies have found that people with mental illnesses such as Schizophrenia had heightened levels of copper in their systems. However it is unknown at this stage whether the copper contributes to the mental illness, whether the body attempts to store more copper in response to the illness, or whether the high levels of copper are the result of the mental illness. Miscellaneous hazards The metal, when powdered, is a Fire Hazard . At concentrations higher than 1 mg/L, copper can stain clothes and items washed in water. Occurrence .]] See Copper Extraction for the main article. The main copper-ore producing countries are Chile , United States , Indonesia , Australia , Peru , Russia , Canada , China , Poland , Kazakhstan and Mexico . .http://www.mii.org/Minerals/photocopper.html Copper can be found as (Cu2O). Most copper in Chile and El Chino Mine in New Mexico . The average abundance of copper found within crustal rocks is approximately 68 Ppm by mass, and 22 ppm by atoms. 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 . The copper price has quintupuled since 1999, rising from $0.60 per Pound in June 1999 to $3.25 per pound in April 2006 {Link without Title} . 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 blue or blue-green salts and solutions. Under unusual conditions, a +3 state can be obtained. 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 penta Hydrate which is perhaps the most familiar copper compound in the laboratory. It is used as a Fungicide , known as Bordeaux mixture. 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 . Copper (I) compounds : Copper(I) Chloride , Copper(I) Oxide . Copper (II) compounds : Copper(II) Carbonate , Copper(II) Chloride , Copper(II) Hydroxide , Copper(II) Nitrate , Copper(II) Oxide , Copper(II) Sulfate , Copper(II) Sulfide . Copper (I) and Copper (II) can also be referred to by their common names cuprous and cupric. ''See also .'' Tests for copper2+ ion Add aqueous Sodium Hydroxide . A blue precipitate of Copper(II) Hydroxide should form, by the displacement of the copper ions by Sodium Ions . Ionic equation: :Cu2+(aq) + 2OH−(aq) → Cu(OH)2 (s) Add aqeuous Ammonia . A precipitate should form, which then dissolves upon adding excess ammonia, to form an ammonia complex, tetraaminecopper(II). Ionic equation: :Cu2+(aq) + 4NH3 (aq) → Cu(NH3)42+(aq) References
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