
[Middle English coper, from Old English, from Late Latin cuprum, from Latin Cyprium (aes), Cyprian (metal), from Cyprius, of Cyprus, from Greek Kuprios, from Kupros, Cyprus.]
coppery cop'per·y adj.For more information on copper, visit Britannica.com.
Background
Copper is one of the basic chemical elements. In its nearly pure state, copper is a reddish-orange metal known for its high thermal and electrical conductivity. It is commonly used to produce a wide variety of products, including electrical wire, cooking pots and pans, pipes and tubes, automobile radiators, and many others. Copper is also used as a pigment and preservative for paper, paint, textiles, and wood. It is combined with zinc to produce brass and with tin to produce bronze.
Copper was first used as early as 10,000 years ago. A copper pendant from about 8700 B.C. was found in what is now northern Iraq. There is evidence that by about 6400 B.C. copper was being melted and cast into objects in the area now known as Turkey. By 4500 B.C., this technology was being practiced in Egypt as well. Most of the copper used before 4000 B.C. came from the random discovery of isolated outcroppings of native copper or from meteorites that had impacted Earth. The first mention of the systematic extraction of copper ore comes from about 3800 B.C. when an Egyptian reference describes mining operations on the Sinai Peninsula.
In about 3000 B.C., large deposits of copper ore were found on the island of Cyprus in the Mediterranean Sea. When the Romans conquered Cyprus, they gave the metal the Latin name aes cyprium, which was often shortened to cyprium. Later this was corrupted to cuprum, from which the English word copper and the chemical symbol Cu are derived.
In South America, copper objects were being produced along the northern coast of Peru as early as 500 B.C., and the development of copper metallurgy was well advanced by the time the Inca empire fell to the conquering Spanish soldiers in the 1500s.
In the United States, the first copper mine was opened in Branby, Connecticut, in 1705, followed by one in Lancaster, Pennsylvania, in 1732. Despite this early production, most copper used in the United States was imported from Chile until 1844, when mining of large deposits of high-grade copper ore around Lake Superior began. The development of more efficient processing techniques in the late-1800s allowed the mining of lower-grade copper ores from huge open-pit mines in the western United States.
Today, the United States and Chile are the world's top two copper producing countries, followed by Russia, Canada, and China.
Raw Materials
Pure copper is rarely found in nature, but is usually combined with other chemicals in the form of copper ores. There are about 15 copper ores mined commercially in 40 countries around the world. The most common are known as sulfide ores in which the copper is chemically bonded with sulfur. Others are known as oxide ores, carbonate ores, or mixed ores depending on the chemicals present. Many copper ores also contain significant quantities of gold, silver, nickel, and other valuable metals, as well as large quantities of commercially useless material. Most of the copper ores mined in the United States contain only about 1.2-1.6% copper by weight.
The most common sulfide ore is chalcopyrite, CuFeS2, also known as copper pyrite or yellow copper ore. Chalcocite, Cu2S, is another sulfide ore.
Cuprite, or red copper ore, Cu2O, is an oxide ore. Malachite, or green copper ore, Cu(OH)2•CuCO3, is an important carbonate ore, as is azurite, or blue copper carbonate, Cu(OH)2•2CuCO3.
Other ores include tennantite, boronite, chrysocolla, and atacamite.
In addition to the ores themselves, several other chemicals are often used to process and refine copper. These include sulfuric acid, oxygen, iron, silica, and various organic compounds, depending on the process used.
The Manufacturing
Process
The process of extracting copper from copper ore varies according to the type of ore and the desired purity of the final product. Each process consists of several steps in which unwanted materials are physically or chemically removed, and the concentration of copper is progressively increased. Some of these steps are conducted at the mine site itself, while others may be conducted at separate facilities.
Here are the steps used to process the sulfide ores commonly found in the western United States.
Mining
Concentrating
The copper ore usually contains a large amount of dirt, clay, and a variety of non-copper bearing minerals. The first step is to remove some of this waste material. This process is called concentrating and is usually done by the flotation method.
Smelting
Once the waste materials have been physically removed from the ore, the remaining copper concentrate must undergo several chemical reactions to remove the iron and sulfur. This process is called smelting and traditionally involves two furnaces as described below. Some modern plants utilize a single furnace, which combines both operations.
Refining
Even though copper blister is 99% pure copper, it still contains high enough levels of sulfur, oxygen, and other impurities to hamper further refining. To remove or adjust the levels of these materials, the blister copper is first fire refined before it is sent to the final electrorefining process.
Casting
Quality Control
Because electrical applications require a very low level of impurities, copper is one of the few common metals that are refined to almost 100% purity. The process described above has been proven to produce copper of very high purity. To ensure this purity, samples are analyzed at various steps to determine whether any adjustment to the process is required.
Byproducts/Waste
The recovery of sulfuric acid from the copper smelting process not only provides a profitable byproduct, but also significantly reduces the air pollution caused by the furnace exhaust. Gold, silver, and other precious metals are also important byproducts.
Waste products include the overburden from the mining operation, the tailings from the concentrating operation, and the slag from the smelting operation. This waste may contain significant concentrations of arsenic, lead, and other chemicals, which pose a potential health hazard to the surrounding area. In the United States, the Environmental Protection Agency (EPA) regulates the storage of such wastes and the remediation of the area once mining and processing operations have ceased. The sheer volume of the material involved—in some cases, billions of tons of waste—makes this a formidable task, but it also presents some potentially profitable opportunities to recover the useable materials contained in this waste.
The Future
Demand for copper is expected to remain high, especially in the electrical and electronics industries. The current trends in copper processing are towards methods and equipment that use less energy and produce less air pollution and solid waste. In the United States, this is a difficult assignment because of the stringent environmental controls and the very low-concentration copper ores that are available. In some cases, the production costs may increase significantly.
One encouraging trend is the increased use of recycled copper. Currently over half the copper being produced in the United States comes from recycled copper. Fifty-five percent of the recycled copper comes from copper machining operations, such as screw forming, and 45% comes from the recovery of used copper products, such as electrical wire and automobile radiators. The percentage of recycled copper is expected to grow as the costs of new copper processing increase.
Where to Learn More
Books
Brady, George S., Henry R. Clauser, and John A. Vaccari. Materials Handbook. McGraw-Hill, 1997.
Heiserman, David L. Exploring Chemical Elements and Their Compounds. TAB Books, 1992.
Hombostel, Caleb. Construction Materials. John Wiley and Sons, Inc., 1991.
Kroschwitz, Jacqueline I. and Mary Howe-Grant, ed. Encyclopedia of Chemical Technology. John Wiley and Sons, Inc., 1993.
Stwertka, Albert. A Guide to the Elements. Oxford University Press, 1996.
Periodicals
Baum, Dan and Margaret L. Knox. "We want people who have a problem with mine wastes to think of Butte." Smithsonian (November 1992): 46-52, 54-57.
Shimada, Izumi and John F. Merkel. "Copper-Alloy Metallurgy in Ancient Peru." Scientific American (July 1991): 80-86.
Other
http://www.intercorr.com/periodic/29.htm.
http://innovations.copper.org/innovations.html.
[Article by: Chris Cavette]
A chemical element, Cu, atomic number 29, atomic weight 63.546. Copper, a nonferrous metal, is the twentieth most abundant element present in the Earth's crust, at an average level of 68 parts per million (0.22 lb/ton or 0.11 kg/metric ton). Copper metal and copper alloys have considerable technological importance due to their combined electrical, mechanical, and physical properties. The discoveries that mixed-valence Cu(II)/Cu(III) oxides exhibit superconductivity (zero electrical resistance) at temperatures as high as 125 K (−234°F; liquid nitrogen, a cheap coolant, boils at 90 K or −297°F) have generated intense international competition to understand these new materials and to develop technological applications. Although some pure copper metal is present in nature, commercial copper is obtained by reduction of the copper compounds in ores followed by electrolytic refining. The rich chemistry of copper is restricted mostly to the valence states Cu(I) and Cu(II); compounds containing Cu(0), Cu(III), and Cu(IV) are uncommon. Soluble copper salts are potent bacteriocides and algicides at low levels and toxic to humans in large doses. Yet copper is an essential trace element that is present in various metalloproteins required for the survival of plants and animals.
Copper is located in the periodic table between nickel and zinc in the first row of transition elements and in the same subgroup as the other so-called coinage metals, silver and gold. The electronic configuration of elemental copper is [1s22s22p63s2] 3d104s1 or [argon]3d104s1. At first glance, the sole 4s electron might suggest chemical similarity to potassium, which has the [argon]4s1 configuration. However, metallic copper, in sharp contrast to metallic potassium, is relatively unreactive. The higher nuclear charge of copper relative to that of potassium is not fully shielded by the 10 additional d electrons, with the result that the copper 4s electron has a higher ionization potential than that of potassium (745.5 versus 418.9 kilojoules/mole, respectively). Moreover, the second and third ionization potentials of copper (1958.1 and 3554 J/mole, respectively) are considerably lower than those of potassium, and account for the higher valence-state accessibility associated with transition-metal chemistry as opposed to alkali-metal chemistry. See also Electron configuration; Periodic table; Transition elements; Valence.
Copper is a comparatively heavy metal. The density of the pure solid is 8.96 g/cm3 (5.18 oz/in.3) at 20°C (68°F). The density of commercial copper varies with method of manufacture, averaging 8.90–8.92 g/cm3 (5.14–5.16 oz/in.3) in cast refinery shapes, 8.93 g/cm3 (5.16 oz/in.3) for annealed tough-pitch copper, and 8.94 g/cm3 (517 oz/in.3) for oxygen-free copper. The density of liquid copper is 8.22 g/cm3 (4.75 oz/in.3) near the freezing point.
The melting point of copper is 1083.0 ∓ 0.1°C (1981.4 ∓ 0.2°F). Its normal boiling point is 2595°C (4703°F).
The coefficient of linear expansion of copper is 1.65 × 10−5/°C at 20°C.
The specific heat of the solid is 0.092 cal/g at 20°C (68°F). The specific heat of liquid copper is 0.112 cal/g, and of copper in the vapor state about 0.08 cal/g.
The electrical resistivity of copper in the usual volumetric unit, that of a cube measuring 1 cm in each direction, is 1.6730 × 10−6 ohm · cm at 20°C (68°F). Only silver has a greater volumetric conductivity than copper. On a relative basis in which silver is rated 100, copper is 94, aluminum 57, and iron 16.
The mass resistivity of pure copper for a length of 1 m weighing 1 g at 20°C (68°F) is 0.14983 ohm. The conductivity of copper on the mass basis is surpassed by several light metals, notably aluminum. The relative values are 100 for aluminum, 50 for copper, and 44 for silver.
By far the largest use of copper is in the electrical industry, and therefore high electrical conductivity is its most important single property, although for industrial use this property must be accompanied by suitable characteristics in other respects. See also Conductor (electricity).
Copper-containing proteins provide diverse biochemical functions, including copper uptake and transport (ceruloplasmin), copper storage (metallothionen), protective roles (superoxide dismutase), catalysis of substrate oxygenation (dopamine β-monooxygenase), biosynthesis of connective tissue (lysyl oxidase), terminal oxidases for oxygen metabolism (cytochrome c oxidase), oxygen transport (hemocyanin), and electron transfer in photosynthetic pathways (plastocyanin). See also Enzyme.
(Cu) A reddish-brown metal that is highly conductive and widely used for electrical wire. When a signal "runs over copper," it means that a metal wire is used rather than a glass wire (optical fiber). See copper chip.
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A dietary essential trace metal, which forms the prosthetic group of a number of enzymes. The Reference Nutrient Intake is 1.2 mg/day. Toxic in excess, and it is recommended that not more than 2-10 mg/day should be consumed habitually. Rich sources include: meat, poultry, game, fish and shellfish, avocado, nuts, pulses, bread, chocolate, beer, cider, coconut, mushrooms.
An essential element involved in many processes including red blood cell formation, respiration, and bone formation. Copper deficiencies are rare, mainly because most domestic water supplies are contaminated with copper from pipes, but low intakes can lead to anaemia. Oysters and liver are good sources of dietary copper. In the UK, the adult Reference Nutrient Intake for copper is 1.2 mg each day. In the USA, the estimated safe and adequate daily intake of copper is 1.5-3.0 mg. Blood levels of copper often decrease after exercise indicating that athletes may need higher than normal intakes. Copper and zinc appear to be antagonistic; high intakes of one tend to reduce the absorption of the other. Copper toxicity is rare, but intakes greater than 20 mg cause vomiting and nausea.
Conventional electron-carrying network cable with a core conductor of copper — or aluminum! Opposed to light pipe or, say, a short-range microwave link.
A lustrous reddish metal, highly ductile and malleable; has high tensile strength, is an excellent electrical and thermal conductor, is available in a wide variety of shapes; widely used for downspouts, electrical conductors, flashing, gutters, roofing, etc.
One of the first metals (Cu) to be exploited by human communities. In its native form it can be worked without prior treatment. It was later extracted from a range of ores: carbonates (including malachite and azurite); oxides (including cuprite and melaconite); and sulphides (including chalcanthite). Shaping could be done by hammering, casting, or a combination of the two. Copper provides the main constituent for a number of alloys, the most widely used being bronze. The development of copper metallurgy happened independently in several parts of the world: in western Asia around 6000 bc; in Europe around 4000 bc; in the Longshan Culture of China around 2500 bc; in South America around 1500 bc in Peru, Bolivia, and Ecuador; ad 100 in central America; and in North America amongst the Old Copper Cultures of the Great Lakes region around 3000 bc.
An essential element involved in many processes including red blood cell formation, blood-sugar regulation, and bone formation. Deficiency may cause anaemia and feelings of lassitude.
| KEY TERMS Antioxidants—Antioxidants are nutrients that deactivate reactive molecules (free radicals) and prevent harmful chain reactions. Lacto-ovo vegetarian—People who do not eat meat, but do include dairy products and eggs in their diets. Minerals—Inorganic chemical elements that are found in plants and animals and are essential for life. There are two types of minerals: major minerals, which the body requires in large amounts, and trace elements, which the body needs only in minute amounts. |
| Age | Recommended Dietary Allowance (mcg/day) |
| Children 0–6 mos | 200 (AI) |
| Children 7–12 mos | 220 (AI) |
| Children 1–3 yrs | 340 |
| Children 4–8 yrs | 440 |
| Children 9–13 yrs | 700 |
| Adolescents 14–18 yrs | 890 |
| Adults 19≥ yrs | 900 |
| Pregnant women | 1,000 |
| Breastfeeding women | 1,300 |
| Food | Copper (mcg) |
| Beef, liver, 3 oz | 1,240 |
| Oysters, cooked, 6 med | 374 |
| Chocolate, semisweet, 1 cup | 176 |
| Mushrooms, shitake, cooked, 1 cup | 130 |
| Cashews, dry roasted, 1 oz | 70 |
| Peas, black-eyed, cooked, ½ cup | 70 |
| Soybeans, boiled, 1 cup | 70 |
| Beans, white, canned, 1 cup | 60 |
| Sunflower seeds, ¼ cup 359 | |
| Chickpeas, cooked, 1 cup | 57 |
| Baked beans, with pork, 1 cup | 54 |
| Lentils, cooked, 1 cup | 50 |
| V-8 juice, canned, 1 cup | 48 |
| Potato skin, baked, 1 | 47 |
| Raisins, seedless, 1 cup | 46 |
| Salmon, baked, 3 oz | 30 |
| AI = Adequate Intake | |
| mcg = microgram |
Properties
Copper is a reddish metal with a face-centered cubic crystalline structure. It is malleable, ductile, and an extremely good conductor of both heat and electricity. It is softer than iron but harder than zinc and can be polished to a bright finish. It is found in Group 11 of the periodic table, together with silver and gold. Copper has low chemical reactivity. In moist air it slowly forms a greenish surface film (usually a mixture of carbonate, sulfate, hydroxide, and oxide) called patina; this coating protects the metal from further attack. Copper dissolves in hot concentrated hydrochloric or sulfuric acid but is little affected by cold solutions of these acids; it also dissolves in nitric acid. Salt water corrodes copper, forming a chloride.
Compounds
The most important chemical compound of copper is copper sulfate pentahydrate, also called bluestone or blue vitriol. Other compounds include Paris green, Bordeaux mixture, a cyanide, a chloride, oxides, and a basic carbonate. Verdigris is basic copper acetate.
Sources and Ores
Small amounts of copper are found uncombined, particularly near Lake Superior in Michigan. Copper ores are found in various parts of the world. In the United States (the chief producer of copper) ores are mined in Arizona, Utah, Montana, New Mexico, Nevada, and Michigan. Copper ores are also found in Canada, South America (in Chile and Peru), S central Africa, Russia (in the Ural Mts.), and to a limited extent in Europe and the British Isles.
The principal ore of copper is chalcopyrite, a sulfide of copper and iron, also called copper pyrite. Other important ores are chalcocite, or copper glance, a shiny lead-gray copper sulfide; bornite, a lustrous reddish-brown sulfide of copper and iron; cuprite, a red cuprous oxide ore; and malachite, a bright green carbonate ore. Azurite is a blue crystalline basic carbonate of copper found with other copper ores. Chrysocolla is a bluish-green copper silicate ore. Another important source of copper is secondary (scrap) copper, which is produced from discarded copper and copper alloys.
Commercial Preparation
Copper metal is prepared commercially in various ways. Copper sulfide ores, usually containing only 1% to 2% copper, are concentrated to 20% to 40% copper by the flotation process. They are then usually roasted to remove some of the sulfur and other impurities, and then smelted with iron oxide in either a blast furnace or a reverberatory furnace to produce copper matte, a molten solution of copper sulfide mixed with small amounts of iron sulfide. The matte is transferred to a converter, where it is treated by blowing air through it to remove the sulfur (as sulfur dioxide, a gas) and the iron (as a slag of ferrous oxide). The resulting copper is 98% to 99% pure; it is called blister copper because its surface is blistered by escaping gases when it solidifies during casting.
Most copper is further purified by electrolysis. The blister copper is refined in a furnace and cast into anodes. Thin sheets of pure copper are used as cathodes. A solution of copper sulfate and sulfuric acid is used as the electrolyte. When the anode and cathode are immersed in the electrolyte and an electric current is passed, the anode is dissolved in the electrolyte and pure copper metal is deposited on the cathode. Soluble impurities, usually nickel and arsenic, remain dissolved in the electrolyte. Insoluble impurities, often including silver, gold, and other valuable metals, settle out of the electrolyte; they may be collected and purified.
Copper oxide ores are usually treated by a different process, called leaching, in which the copper in the ore is dissolved in a leaching solution (usually dilute sulfuric acid); pure copper is recovered by electrolysis. Alternatively, the solution is treated with iron to precipitate the so-called cement copper, which is impure.
Importance and Uses
Copper is present in minute amounts in the animal body and is essential to normal metabolism. It is a component of hemocyanin, the blue, oxygen-carrying blood pigment of lobsters and other large crustaceans. It is needed in the synthesis of hemoglobin, the red, oxygen-carrying pigment found in the blood of humans, although it is not a component of hemoglobin.
The chief commercial use of copper is based on its electrical conductivity (second only to that of silver); about half the total annual output of copper is employed in the manufacture of electrical apparatus and wire. Copper is also used extensively as roofing, in making copper utensils, and for coins and metalwork. Copper tubing is used in plumbing, and, because of its high heat conductivity, in heat-exchanging devices such as refrigerator and air-conditioner coils. Powdered copper is sometimes used as a pigment in paints. An important use of copper is in alloys such as brass, bronze, gunmetal, Monel metal, and German silver. Compounds of copper are widely used as insecticides and fungicides; as pigments in paints; as mordants (fixatives) in dyeing; and in electroplating.
Environment
In the upper levels of copper sulfide veins and in some types of volcanic rock.
Crystal descriptionUsually in distorted, often rounded, complex crystals, with cubes, dodecahedrons, and octahedrons predominant. Often in hackly masses (Michigan) and in sheets without recognizable crystal forms.
Physical propertiesCopper color. Luster metallic; hardness 2Ɖ-3; specific gravity 8.9. Malleable and ductile.
CompositionFairly pure as a rule, often alloyed with small amounts of silver, arsenic, iron, etc.
TestsSmall bits fuse on charcoal to black-coated copper button; malleable, soluble in acids, giving greenish solutions. Colors flame blue-green.
Distinguishing characteristicsAlmost inescapable green and blue stains on rock outcrops, known as "copper blooms," are a guide to deposits of copper and its associated minerals. The malleability and the color are distinguishing characteristics.
OccurrenceSince weathering processes free copper from its primary ore, chalcopyrite (CuFeS 2 ), it is likely to be found in the cap rock (the gossan) of copper-bearing sulfide veins, particularly in arid climates. Native copper is also found in ancient lava flows, where iron and oxygen have robbed the magma of sulfur. It is abundant in this form in Michigan's Upper Peninsula, where copper has been deposited in a thick series of flows, and this is the only economic source where all the copper is in the native state. Great masses found in these deposits were hard to remove because of their size and the difficulty of breaking them up. Nuggets from this deposit carried south by the glacier were scattered across the north-central states and were manufactured by the Indians into copper artifacts. Native copper was once found in Chessy, France, and Cornwall, England. Today it is abundant in some of the Arizona mines still working in the upper levels, like Morenci and Ajo. Surprisingly, it is not a major mineral in Chile, though that country contains rich sources of the metal.
They discovered the plumbing was made of copper pipes.
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A chemical element, atomic number 29, atomic weight 63.54, symbol Cu. It is necessary for bone formation and for the formation of blood because it occurs in several oxidative enzymes including one involved in the transformation of inorganic iron into hemoglobin.
A malleable, reddish-brown metallic element. Copper is a component of several important enzymes in the body and is essential to good health. Copper deficiency is rare, because only 2 to 5 mg daily are necessary, and that amount is easily obtained in a normal diet.

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| Appearance | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| red-orange metallic luster Native copper (~4 cm in size) |
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| General properties | |||||||||||||||||||
| Name, symbol, number | copper, Cu, 29 | ||||||||||||||||||
| Pronunciation | /ˈkɒpər/ KOP-ər | ||||||||||||||||||
| Element category | transition metal | ||||||||||||||||||
| Group, period, block | 11, 4, d | ||||||||||||||||||
| Standard atomic weight | 63.546(3) | ||||||||||||||||||
| Electron configuration | [Ar] 3d10 4s1 | ||||||||||||||||||
| Electrons per shell | 2, 8, 18, 1 (Image) | ||||||||||||||||||
| Physical properties | |||||||||||||||||||
| Phase | solid | ||||||||||||||||||
| Density (near r.t.) | 8.94 g·cm−3 | ||||||||||||||||||
| Liquid density at m.p. | 8.02 g·cm−3 | ||||||||||||||||||
| Melting point | 1357.77 K, 1084.62 °C, 1984.32 °F | ||||||||||||||||||
| Boiling point | 2835 K, 2562 °C, 4643 °F | ||||||||||||||||||
| Heat of fusion | 13.26 kJ·mol−1 | ||||||||||||||||||
| Heat of vaporization | 300.4 kJ·mol−1 | ||||||||||||||||||
| Molar heat capacity | 24.440 J·mol−1·K−1 | ||||||||||||||||||
| Vapor pressure | |||||||||||||||||||
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| Atomic properties | |||||||||||||||||||
| Oxidation states | +1, +2, +3, +4 (mildly basic oxide) |
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| Electronegativity | 1.90 (Pauling scale) | ||||||||||||||||||
| Ionization energies (more) |
1st: 745.5 kJ·mol−1 | ||||||||||||||||||
| 2nd: 1957.9 kJ·mol−1 | |||||||||||||||||||
| 3rd: 3555 kJ·mol−1 | |||||||||||||||||||
| Atomic radius | 128 pm | ||||||||||||||||||
| Covalent radius | 132±4 pm | ||||||||||||||||||
| Van der Waals radius | 140 pm | ||||||||||||||||||
| Miscellanea | |||||||||||||||||||
| Crystal structure | face-centered cubic | ||||||||||||||||||
| Magnetic ordering | diamagnetic[1] | ||||||||||||||||||
| Electrical resistivity | (20 °C) 16.78 nΩ·m | ||||||||||||||||||
| Thermal conductivity | 401 W·m−1·K−1 | ||||||||||||||||||
| Thermal expansion | (25 °C) 16.5 µm·m−1·K−1 | ||||||||||||||||||
| Speed of sound (thin rod) | (r.t.) (annealed) 3810 m·s−1 |
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| Young's modulus | 110–128 GPa | ||||||||||||||||||
| Shear modulus | 48 GPa | ||||||||||||||||||
| Bulk modulus | 140 GPa | ||||||||||||||||||
| Poisson ratio | 0.34 | ||||||||||||||||||
| Mohs hardness | 3.0 | ||||||||||||||||||
| Vickers hardness | 369 MPa | ||||||||||||||||||
| Brinell hardness | 874 MPa | ||||||||||||||||||
| CAS registry number | 7440-50-8 | ||||||||||||||||||
| Most stable isotopes | |||||||||||||||||||
| Main article: Isotopes of copper | |||||||||||||||||||
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Copper (
/ˈkɒpər/ KOP-ər) is a chemical element with the symbol Cu (from Latin: cuprum) and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; a freshly exposed surface has a reddish-orange color. It is used as a conductor of heat and electricity, a building material, and a constituent of various metal alloys.
The metal and its alloys have been used for thousands of years. In the Roman era, copper was principally mined on Cyprus, hence the origin of the name of the metal as сyprium (metal of Cyprus), later shortened to сuprum. Its compounds are commonly encountered as copper(II) salts, which often impart blue or green colors to minerals such as turquoise and have been widely used historically as pigments. Architectural structures built with copper corrode to give green verdigris (or patina). Decorative art prominently features copper, both by itself and as part of pigments.
Copper(II) ions are water-soluble, where they function at low concentration as bacteriostatic substances, fungicides, and wood preservatives. In sufficient amounts, they are poisonous to higher organisms; at lower concentrations it is an essential trace nutrient to all higher plant and animal life. The main areas where copper is found in animals are liver, muscle and bone.
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Contents
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Copper, silver and gold are in group 11 of the periodic table, and they share certain attributes: they have one s-orbital electron on top of a filled d-electron shell and are characterized by high ductility and electrical conductivity. The filled d-shells in these elements do not contribute much to the interatomic interactions, which are dominated by the s-electrons through metallic bonds. Contrary to metals with incomplete d-shells, metallic bonds in copper are lacking a covalent character and are relatively weak. This explains the low hardness and high ductility of single crystals of copper.[2] At the macroscopic scale, introduction of extended defects to the crystal lattice, such as grain boundaries, hinders flow of the material under applied stress thereby increasing its hardness. For this reason, copper is usually supplied in a fine-grained polycrystalline form, which has greater strength than monocrystalline forms.[3]
The low hardness of copper partly explains its high electrical (59.6×106 S/m) and thus also high thermal conductivity, which are the second highest among pure metals at room temperature.[4] This is because the resistivity to electron transport in metals at room temperature mostly originates from scattering of electrons on thermal vibrations of the lattice, which are relatively weak for a soft metal.[2] The maximum permissible current density of copper in open air is approximately 3.1×106 A/m2 of cross-sectional area, above which it begins to heat excessively.[5] As with other metals, if copper is placed against another metal, galvanic corrosion will occur.[6]
Together with osmium (bluish), and gold (yellow), copper is one of only three elemental metals with a natural color other than gray or silver.[7] Pure copper is orange-red and acquires a reddish tarnish when exposed to air. The characteristic color of copper results from the electronic transitions between the filled 3d and half-empty 4s atomic shells – the energy difference between these shells is such that it corresponds to orange light. The same mechanism accounts for the yellow color of gold.[2]
Copper forms a rich variety of compounds with oxidation states +1 and +2, which are often called cuprous and cupric, respectively.[8] It does not react with water, but it slowly reacts with atmospheric oxygen forming a layer of brown-black copper oxide. In contrast to the oxidation of iron by wet air, this oxide layer stops the further, bulk corrosion. A green layer of verdigris (copper carbonate) can often be seen on old copper constructions, such as the Statue of Liberty, the largest copper statue in the world built using repoussé and chasing.[9] Hydrogen sulfides and sulfides react with copper to form various copper sulfides on the surface. In the latter case, the copper corrodes, as is seen when copper is exposed to air containing sulfur compounds.[10] Oxygen-containing ammonia solutions give water-soluble complexes with copper, as do oxygen and hydrochloric acid to form copper chlorides and acidified hydrogen peroxide to form copper(II) salts. Copper(II) chloride and copper comproportionate to form copper(I) chloride.[11]
There are 29 isotopes of copper. 63Cu and 65Cu are stable, with 63Cu comprising approximately 69% of naturally occurring copper; they both have a spin of 3/2.[12] The other isotopes are radioactive, with the most stable being 67Cu with a half-life of 61.83 hours.[12] Seven metastable isotopes have been characterized, with 68mCu the longest-lived with a half-life of 3.8 minutes. Isotopes with a mass number above 64 decay by β-, whereas those with a mass number below 64 decay by β+. 64Cu, which has a half-life of 12.7 hours, decays both ways.[13]
62Cu and 64Cu have significant applications. 64Cu is a radiocontrast for X-ray imaging, and complexed with a chelate can be used for treating cancer. 62Cu is used in 62Cu-PTSM that is a radioactive tracer for positron emission tomography.[14]
Copper can be found as either native copper or as part of minerals. Native copper is a polycrystal, with the largest described single crystal measuring 4.4×3.2×3.2 cm.[15] The largest mass of elemental copper weighed 420 tonnes and was found in 1857 on the Keweenaw Peninsula in Michigan, US.[16] There are many examples of copper-containing minerals: chalcopyrite and chalcocite are copper sulfides, azurite and malachite are copper carbonates and cuprite is a copper oxide.[4] Copper is present in the Earth's crust at a concentration of about 50 parts per million (ppm),[16] and is also synthesized in massive stars.[17]
Most copper is mined or extracted as copper sulfides from large open pit mines in porphyry copper deposits that contain 0.4 to 1.0% copper. Examples include Chuquicamata in Chile, Bingham Canyon Mine in Utah, United States and El Chino Mine in New Mexico, United States. According to the British Geological Survey, in 2005, Chile was the top mine producer of copper with at least one-third world share followed by the United States, Indonesia and Peru.[4] The amount of copper in use is increasing and the quantity available is barely sufficient to allow all countries to reach developed world levels of usage.[18]
Copper has been in use at least 10,000 years, but more than 95% of all copper ever mined and smelted has been extracted since 1900. As with many natural resources, the total amount of copper on Earth is vast (around 1014 tons just in the top kilometer of Earth's crust, or about 5 million years worth at the current rate of extraction). However, only a tiny fraction of these reserves is economically viable, given present-day prices and technologies. Various estimates of existing copper reserves available for mining vary from 25 years to 60 years, depending on core assumptions such as the growth rate.[19] Recycling is a major source of copper in the modern world.[20] Because of these and other factors, the future of copper production and supply is the subject of much debate, including the concept of Peak copper, analogous to Peak Oil.
The price of copper has historically been unstable,[21] and it quintupled from the 60-year low of US$0.60/lb (US$1.32/kg) in June 1999 to US$3.75 per pound (US$8.27/kg) in May 2006. It dropped to US$2.40/lb (US$5.29/kg) in February 2007, then rebounded to US$3.50/lb (US$7.71/kg) in April 2007.[22] In February 2009, weakening global demand and a steep fall in commodity prices since the previous year's highs left copper prices at US$1.51/lb.[23]
The concentration of copper in ores averages only 0.6%, and most commercial ores are sulfides, especially chalcopyrite (CuFeS2) and to a lesser extent chalcocite (Cu2S).[24] These minerals are concentrated from crushed ores to the level of 10–15% copper by froth flotation or bioleaching.[25] Heating this material with silica in flash smelting removes much of the iron as slag. The process exploits the greater ease of converting iron sulfides into its oxides, which in turn react with the silica to form the silicate slag, which floats on top of the heated mass. The resulting copper matte consisting of Cu2S is then roasted to convert all sulfides into oxides:[24]
The cuprous oxide is converted to blister copper upon heating:
The Sudbury matte process converted only half the sulfide to oxide and then used this oxide to remove the rest of the sulfur as oxide. It was then electrolytically refined and the anode mud exploited for the platinum and gold it contained. This step exploits the relatively easy reduction of copper oxides to copper metal. Natural gas is blown across the blister to remove most of the remaining oxygen and electrorefining is performed on the resulting material to produce pure copper:[26]
Copper, like aluminium, is 100% recyclable without any loss of quality whether in a raw state or contained in a manufactured product. In volume, copper is the third most recycled metal after iron and aluminium. It is estimated that 80% of the copper ever mined is still in use today.[27] According to the International Resource Panel's Metal Stocks in Society report, the global per capita stock of Copper in use in society is 35–55 kg. Much of this is in more-developed countries (140–300 kg per capita) rather than less-developed countries (30–40 kg per capita).
The process of recycling copper follows roughly the same steps as is used to extract copper, but requires fewer steps. High purity scrap copper is melted in a furnace and then reduced and cast into billets and ingots; lower purity scrap is refined by electroplating in a bath of sulfuric acid.[28]
As for other elements, the simplest compounds of copper are binary compounds, i.e. those containing only two elements. The principal ones are the oxides, sulfides and halides. Both cuprous and cupric oxides are known. Among the numerous copper sulfides, important examples include copper(I) sulfide and copper(II) sulfide.
The cuprous halides with chlorine, bromine, and iodine are known, as are the cupric halides with fluorine, chlorine, and bromine. Attempts to prepare copper(II) iodide give cuprous iodide and iodine.[8]
Copper, like all metals, forms coordination complexes with ligands. In aqueous solution, copper(II) exists as [Cu(H2O)6]2+. This complex exhibits the fastest water exchange rate (speed of water ligands attaching and detaching) for any transition metal aquo complex. Adding aqueous sodium hydroxide causes the precipitation of light blue solid copper(II) hydroxide. A simplified equation is:
Aqueous ammonia results in the same precipitate. Upon adding excess ammonia, the precipitate dissolves, forming tetraamminecopper(II):
Many other oxyanions form complexes; these include copper(II) acetate, copper(II) nitrate, and copper(II) carbonate. Copper(II) sulfate forms a blue crystalline pentahydrate, which is the most familiar copper compound in the laboratory. It is used in a fungicide called the Bordeaux mixture.[29]
Polyols, compounds containing more than one alcohol functional group, generally interact with cupric salts. For example, copper salts are used to test for reducing sugars. Specifically, using Benedict's reagent and Fehling's solution the presence of the sugar is signaled by a color change from blue Cu(II) to reddish copper(I) oxide.[30] Schweizer's reagent and related complexes with ethylenediamine and other amines dissolve cellulose.[31] Amino acids form very stable chelate complexes with copper(II). Many wet-chemical tests for copper ions exist, one involving potassium ferrocyanide, which gives a brown precipitate with copper(II) salts.
Compounds that contain a carbon-copper bond are known as organocopper compounds. They are very reactive towards oxygen to form copper(I) oxide and have many uses in chemistry. They are synthesized by treating copper(I) compounds with Grignard reagents, terminal alkynes or organolithium reagents;[32] in particular, the last reaction described produces a Gilman reagent. These can undergo substitution with alkyl halides to form coupling products; as such, they are important in the field of organic synthesis. Copper(I) acetylide is highly shock-sensitive but is an intermediate in reactions such as the Cadiot-Chodkiewicz coupling[33] and the Sonogashira coupling.[34] Conjugate addition to enones[35] and carbocupration of alkynes[36] can also be achieved with organocopper compounds. Copper(I) forms a variety of weak complexes with alkenes and carbon monoxide, especially in the presence of amine ligands.[37]
Complexes of copper(III) are frequent intermediates in reactions of organocopper compounds. Dicopper oxo complexes also feature copper(III).[38] Fluoride ligands, being highly basic, stabilize metal ions in high oxidation states; indeed, representative copper(III) and copper(IV) complex are fluorides. These include K3CuF6 and Cs2CuF6.[8] With di- and tripeptides, purple-colored complexes of copper(III) have been observed, this high oxidation state being stabilized by the deprotonated amide ligands.[39]
Copper occurs naturally as native copper and was known to some of the oldest civilizations on record. It has a history of use that is at least 10,000 years old, and estimates of its discovery place it at 9000 BC in the Middle East;[40] a copper pendant was found in northern Iraq that dates to 8700 BC.[41] There is evidence that gold and meteoric iron (but not iron smelting) were the only metals used by humans before copper.[42] The history of copper metallurgy is thought to have followed the following sequence: 1) cold working of native copper, 2) annealing, 3) smelting, and 4) the lost wax method. In southeastern Anatolia, all four of these metallurgical techniques appears more or less simultaneously at the beginning of the Neolothic c. 7500 BC.[43] However, just as agriculture was independently invented in several parts of the world (including Pakistan, China, and the Americas) copper smelting was invented locally in several different places. It was probably discovered independently in China before 2800 BC, in Central America perhaps around 600 AD, and in West Africa about the 9th or 10th century AD.[44] Investment casting was invented in 4500–4000 BC in Southeast Asia[40] and carbon dating has established mining at Alderley Edge in Cheshire, UK at 2280 to 1890 BC.[45] Ötzi the Iceman, a male dated from 3300–3200 BC, was found with an axe with a copper head 99.7% pure; high levels of arsenic in his hair suggest his involvement in copper smelting.[46] Experience with copper has assisted the development of other metals; in particular, copper smelting led to the discovery of iron smelting.[46] Production in the Old Copper Complex in Michigan and Wisconsin is dated between 6000 and 3000 BC.[47][48] Natural bronze, a type of copper made from ores rich in silicon, arsenic, and (rarely) tin, came into general use in the Balkans around 5500 BC. Previously the only tool made of copper had been the awl, used for punching holes in leather and gouging out peg-holes for wood joining. However, the introduction of a more robust form of copper led to the widespread use, and large-scale production of heavy metal tools, including axes, adzes, and axe-adzes.[citation needed]
Alloying copper with tin to make bronze was first practiced about 4000 years after the discovery of copper smelting, and about 2000 years after "natural bronze" had come into general use. Bronze artifacts from Sumerian cities and Egyptian artifacts of copper and bronze alloys date to 3000 BC.[49] The Bronze Age began in Southeastern Europe around 3700 - 3300 BC, in Northwestern Europe about 2500 BC. It ended with the beginning of the Iron Age, 2000-1000 BC in the Near East, 600 BC in Northern Europe. The transition between the Neolithic period and the Bronze Age was formerly termed the Chalcolithic period (copper-stone), with copper tools being used with stone tools. This term has gradually fallen out of favor because in some parts of the world the Calcholithic and Neolithic are coterminous at both ends. Brass, an alloy of copper and zinc, is of much more recent origin. It was known to the Greeks, but became a significant supplement to bronze during the Roman Empire.[49]
In Greece, copper was known by the name chalkos (χαλκός). It was an important resource for the Romans, Greeks and other ancient peoples. In Roman times, it was known as aes Cyprium, aes being the generic Latin term for copper alloys and Cyprium from Cyprus, where much copper was mined. The phrase was simplified to cuprum, hence the English copper. Aphrodite and Venus represented copper in mythology and alchemy, due to its lustrous beauty, its ancient use in producing mirrors, and its association with Cyprus, which was sacred to the goddess. The seven heavenly bodies known to the ancients were associated with the seven metals known in antiquity, and Venus was assigned to copper.[50]
Britain's first use of brass occurred around the 3rd–2nd century BC. In North America, copper mining began with marginal workings by Native Americans. Native copper is known to have been extracted from sites on Isle Royale with primitive stone tools between 800 and 1600.[51] Copper metallurgy was flourishing in South America, particularly in Peru around 1000 AD; it proceeded at a much slower rate on other continents. Copper burial ornamentals from the 15th century have been uncovered, but the metal's commercial production did not start until the early 20th century.
The cultural role of copper has been important, particularly in currency. Romans in the 6th through 3rd centuries BC used copper lumps as money. At first, the copper itself was valued, but gradually the shape and look of the copper became more important. Julius Caesar had his own coins made from brass, while Octavianus Augustus Caesar's coins were made from Cu-Pb-Sn alloys. With an estimated annual output of around 15,000 t, Roman copper mining and smelting activities reached a scale unsurpassed until the time of the Industrial Revolution; the provinces most intensely mined were those of Hispania, Cyprus and in Central Europe.[52][53]
The gates of the Temple of Jerusalem used Corinthian bronze made by depletion gilding. It was most prevalent in Alexandria, where alchemy is thought to have begun.[54] In ancient India, copper was used in the holistic medical science Ayurveda for surgical instruments and other medical equipment. Ancient Egyptians (~2400 BC) used copper for sterilizing wounds and drinking water, and later on for headaches, burns, and itching. The Baghdad Battery, with copper cylinders soldered to lead, dates back to 248 BC to AD 226 and resembles a galvanic cell, leading people to believe this was the first battery; the claim has not been verified.[55]
The Great Copper Mountain was a mine in Falun, Sweden, that operated from the 10th century to 1992. It produced two thirds of Europe's copper demand in the 17th century and helped fund many of Sweden's wars during that time.[56] It was referred to as the nation's treasury; Sweden had a copper backed currency.[57]
The uses of copper in art were not limited to currency: it was used by Renaissance sculptors, in photographic technology known as the daguerreotype, and the Statue of Liberty. Copper plating and copper sheathing for ships' hulls was widespread; the ships of Christopher Columbus were among the earliest to have this feature.[58] The Norddeutsche Affinerie in Hamburg was the first modern electroplating plant starting its production in 1876.[59] The German scientist Gottfried Osann invented powder metallurgy in 1830 while determining the metal's atomic mass; around then it was discovered that the amount and type of alloying element (e.g., tin) to copper would affect bell tones. Flash smelting was developed by Outokumpu in Finland and first applied at Harjavalta in 1949; the energy-efficient process accounts for 50% of the world’s primary copper production.[60]
The Intergovernmental Council of Copper Exporting Countries, formed in 1967 with Chile, Peru, Zaire and Zambia, played a similar role for copper as OPEC does for oil. It never achieved the same influence, particularly because the second-largest producer, the United States, was never a member; it was dissolved in 1988.[61]
The major applications of copper are in electrical wires (60%), roofing and plumbing (20%) and industrial machinery (15%). Copper is mostly used as a metal, but when a higher hardness is required it is combined with other elements to make an alloy (5% of total use) such as brass and bronze.[16] A small part of copper supply is used in production of compounds for nutritional supplements and fungicides in agriculture.[29][62] Machining of copper is possible, although it is usually necessary to use an alloy for intricate parts to get good machinability characteristics.
The electrical properties of copper are exploited in copper wires and devices such as electromagnets. Integrated circuits and printed circuit boards increasingly feature copper in place of aluminium because of its superior electrical conductivity (see Copper interconnect for main article); heat sinks and heat exchangers use copper as a result of its superior heat dissipation capacity to aluminium. Vacuum tubes, cathode ray tubes, and the magnetrons in microwave ovens use copper, as do wave guides for microwave radiation.[63]
Copper’s greater conductivity versus other metallic materials enhances the electrical energy efficiency of motors.[64] This is important because motors and motor-driven systems account for 43%-46% of all global electricity consumption and 69% of all electricity used by industry.[65] Increasing the mass and cross section of copper in a coil increases the electrical energy efficiency of the motor. Copper motor rotors, a new technology designed for motor applications where energy savings are prime design objectives,[66][67] are enabling general-purpose induction motors to meet and exceed National Electrical Manufacturers Association (NEMA) premium efficiency standards.[68]
Because of the waterproof nature of copper, it has been used as the roofing material of many buildings since ancient times. The green color on these buildings is due to a long-term chemical reaction: copper is first oxidized to copper(II) oxide, then to cuprous and cupric sulfide and finally to copper(II) carbonate, also called verdigris, which is highly corrosion-resistant.[69] The copper used in this application is phosphorus deoxidized copper (Cu-DHP).[70] Lightning rods use copper as a means to divert electric current throughout the ground instead of destroying the main structure.[71] Copper has excellent brazing and soldering properties and can be welded; the best results are obtained with gas metal arc welding.[72]
Numerous copper alloys exist, many with important uses. Brass is an alloy of copper and zinc and bronze usually refers to copper-tin alloys, but can refer to any alloy of copper such as aluminium bronze. Copper is one of the most important constituents of carat silver and gold alloys and carat solders used in the jewelry industry, modifying the color, hardness and melting point of the resulting alloys.[73]
The alloy of copper and nickel, called cupronickel, is used in low-denomination statuary coins, often for the outer cladding. The US 5-cent coin called nickel consists of 75% copper and 25% nickel and has a homogeneous composition. The 90% copper/10% nickel alloy is remarkable by its resistance to corrosion and is used in various parts being exposed to seawater. Alloys of copper with aluminium (about 7%) have a pleasant golden color and are used in decorations.[16] Copper alloys with tin are part of lead-free solders.[74]
Copper has long been used as a biostatic surface to line parts of ships to protect against barnacles and mussels. It was originally used pure, but has since been superseded by Muntz metal. Bacteria will not grow on a copper surface because it is biostatic. Similarly, as discussed in copper alloys in aquaculture, copper alloys have become important netting materials in the aquaculture industry for the fact that they are antimicrobial and prevent biofouling even in extreme conditions[75] and have strong structural and corrosion-resistant[76] properties in marine environments.
Copper compounds in liquid form are used as a wood preservative, particularly in treating original portion of structures during restoration of damage due to dry rot. Together with zinc, copper wires may be placed over non-conductive roofing materials to discourage the growth of moss. Textile fibers use copper to create antimicrobial protective fabrics,[77] as do ceramic glazes, stained glass and musical instruments. Electroplating commonly uses copper as a base for other metals such as nickel.
Copper is one of three metals, along with lead and silver, used in a museum materials testing procedure called the Oddy test. In this procedure, copper is used to detect chlorides, oxides, and sulfur compounds.
Copper is also commonly found in jewelry, and folklore states that copper bracelets relieve arthritis symptoms, though this is not proven.[78]
Copper proteins have diverse roles in biological electron transport and oxygen transportation, processes that exploit the easy interconversion of Cu(I) and Cu(II).[79] The biological role for copper commenced with the appearance of oxygen in earth's atmosphere.[80] The protein hemocyanin is the oxygen carrier in most mollusks and some arthropods such as the horseshoe crab (Limulus polyphemus).[81] Because hemocyanin is blue, these organisms have blue blood, not the red blood found in organisms that rely on hemoglobin for this purpose. Structurally related to hemocyanin are the laccases and tyrosinases. Instead of reversibly binding oxygen, these proteins hydroxylate substrates, illustrated by their role in the formation of lacquers.[79]
Copper is also a component of other proteins associated with the processing of oxygen. In cytochrome c oxidase, which is required for aerobic respiration, copper and iron cooperate in the reduction of oxygen. Copper is also found in many superoxide dismutases, proteins that detoxify superoxides, by converting it (by disproportionation) to oxygen and hydrogen peroxide:
Several copper proteins, such as the "blue copper proteins", do not interact directly with substrates, hence they are not enzymes. These proteins relay electrons by the process called electron transfer.[79]
Copper is an essential trace element in plants and animals, but not some microorganisms. The human body contains copper at a level of about 1.4 to 2.1 mg per kg of body mass.[82] Stated differently, the RDA for copper in normal healthy adults is quoted as 0.97 mg/day and as 3.0 mg/day.[83] Copper is absorbed in the gut, then transported to the liver bound to albumin.[84] After processing in the liver, copper is distributed to other tissues in a second phase. Copper transport here involves the protein ceruloplasmin, which carries the majority of copper in blood. Ceruloplasmin also carries copper that is excreted in in milk, and is particularly well-absorbed as a copper source. [85]. Copper in the body normally undergoes enterohepatic circulation (about 5 mg a day, vs. about 1 mg per day absorbed in the diet and excreted from the body), and the body is able to excrete some excess copper, if needed, via bile, which carries some copper out of the liver that is not then reabsorbed by the intestine.[86] [87]
Because of its role in facilitating iron uptake, copper deficiency can produce anemia-like symptoms, neutropenia, bone abnormalities, hypopigmentation, impaired growth, increased incidence of infections, osteoporosis, and abnormalities in glucose and cholesterol metabolism. Conversely, an accumulation of copper in body tissues causes Wilson's disease. Severe deficiency can be found by testing for low plasma or serum copper levels, low ceruloplasmin, and low red blood cell superoxide dismutase levels; these are not sensitive to marginal copper status. The "cytochrome c oxidase activity of leucocytes and platelets" has been stated as another factor in deficiency, but the results have not been confirmed by replication.[88]
Numerous antimicrobial efficacy studies have been conducted in the past 10 years regarding copper’s efficacy to destroy a wide range of bacteria, as well as influenza A virus, adenovirus, and fungi.[89]
Copper-alloy touch surfaces have natural intrinsic properties to destroy a wide range of microorganisms (e.g., E. coli O157:H7, methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus, Clostridium difficile, influenza A virus, adenovirus, and fungi).[89] Some 355 copper alloys were proven to kill more than 99.9% of disease-causing bacteria within just two hours when cleaned regularly.[90] The United States Environmental Protection Agency (EPA) has approved the registrations of these copper alloys as “antimicrobial materials with public health benefits,"[90] which allows manufacturers to legally make claims as to the positive public health benefits of products made with registered antimicrobial copper alloys. In addition, the EPA has approved a long list of antimicrobial copper products made from these alloys, such as bedrails, handrails, over-bed tables, sinks, faucets, door knobs, toilet hardware, computer keyboards, health club equipment, shopping cart handles, etc. (for a comprehensive list of products, see: Antimicrobial copper-alloy touch surfaces#Approved products). Copper doorknobs are used by hospitals to reduce the transfer of disease, and Legionnaires' disease is suppressed by copper tubing in plumbing systems.[91] Antimicrobial copper alloy products are now being installed in healthcare facilities in the U.K., Ireland, Japan, Korea, France, Denmark, and Brazil and in the subway transit system in Santiago, Chile, where copper-zinc alloy handrails will be installed in some 30 stations between 2011–2014.[92][93][94]
Gram quantities of various copper salts have been taken in suicide attempts and produced acute copper toxicity in humans, possibly due to redox cycling and the generation of reactive oxygen species that damage DNA.[95] Corresponding amounts of copper salts (30 mg/kg) are toxic in animals.[96] A minimum dietary value for healthy growth in rabbits has been reported to be at least 3 ppm in the diet.[97] However, higher concentrations of copper (100 ppm, 200 ppm, or 500 ppm) in the diet of rabbits may favorably influence feed conversion efficiency, growth rates, and carcass dressing percentages.[98]
Chronic copper toxicity does not normally occur in humans because of transport systems that regulate absorption and excretion. Autosomal recessive mutations in copper transport proteins can disable these systems, leading to Wilson's disease with copper accumulation and cirrhosis of the liver in persons who have inherited two defective genes.[82]
| in pure water, or acidic or alkali conditions. Copper in neutral water is more noble than hydrogen. | in water containing sulfide | in 10 M ammonia solution | in a chloride solution |
| Wikimedia Commons has media related to: Copper |
| Look up copper in Wiktionary, the free dictionary. |
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| Li | Be | B | C | N | O | F | Ne | |||||||||||||||||||||||||||||||||||
| Na | Mg | Al | Si | P | S | Cl | Ar | |||||||||||||||||||||||||||||||||||
| K | Ca | Sc | Ti | V | Cr | Mn | Fe | Co | Ni | Cu | Zn | Ga | Ge | As | Se | Br | Kr | |||||||||||||||||||||||||
| Rb | Sr | Y | Zr | Nb | Mo | Tc | Ru | Rh | Pd | Ag | Cd | In | Sn | Sb | Te | I | Xe | |||||||||||||||||||||||||
| Cs | Ba | La | Ce | Pr | Nd | Pm | Sm | Eu | Gd | Tb | Dy | Ho | Er | Tm | Yb | Lu | Hf | Ta | W | Re | Os | Ir | Pt | Au | Hg | Tl | Pb | Bi | Po | At | Rn | |||||||||||
| Fr | Ra | Ac | Th | Pa | U | Np | Pu | Am | Cm | Bk | Cf | Es | Fm | Md | No | Lr | Rf | Db | Sg | Bh | Hs | Mt | Ds | Rg | Cn | Uut | Uuq | Uup | Uuh | Uus | Uuo | |||||||||||
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This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
Dansk (Danish)
1.
n. - kobber, kobbermønt, gruekedel, plettet ildfugl
v. tr. - forkobre
idioms:
2.
n. - [sl] politibetjent, strisser
Nederlands (Dutch)
(rood)koper, (mv) kopergeld, koperkleurig, ketel, koperen, politieagent, vuurvlinder, verkoperen
Français (French)
1.
n. - (Chim) cuivre, couleur cuivre, (GB) petite monnaie, (GB, Hist) lessiveuse
v. tr. - enduire, couvrir, ou protéger de cuivre
idioms:
2.
n. - agent de police, flic (fam)
Deutsch (German)
1.
n. - Kupfer, Kupfermünze, Kupferkessel
v. - verkupfern, mit Kupfer beschlagen
idioms:
2.
n. - Polizist
Ελληνική (Greek)
n. - χαλκός (κν. μπακίρι), (καθομ.) αστυνομικός, μπάτσος
adj. - χάλκινος
idioms:
Italiano (Italian)
rame, poliziotto, di rame
idioms:
Português (Portuguese)
n. - cobre (m), moeda (f)
adj. - de cobre
idioms:
Русский (Russian)
медь, полицейский, медный, бурый
idioms:
Español (Spanish)
1.
n. - cobre, de cobre
v. tr. - cubrir con cobre
idioms:
2.
n. - agente de policía, policía
Svenska (Swedish)
n. - koppar, kopparmynt, stor kopparkittel, kopparrött, snut (sl.)
adj. - koppar-, kopparröd
中文(简体)(Chinese (Simplified))
1. 铜, 铜币, 铜制品, 红铜色, 镀铜于, 覆以铜皮
idioms:
2. 警察
中文(繁體)(Chinese (Traditional))
1.
n. - 警察
2.
n. - 銅, 銅幣, 銅製品, 紅銅色
v. tr. - 鍍銅於, 覆以銅皮
idioms:
한국어 (Korean)
1.
n. - 구리, 동전, 취사용 보일러
v. tr. - 구리로 싸다, ~에 반대하여 돈을 걸다
2.
n. - 순경, 밀고자, 감형
日本語 (Japanese)
n. - 銅, 銅貨, 銅製品
adj. - 銅製の, 赤銅色の, 銅の
idioms:
العربيه (Arabic)
(الاسم) نحاس, , شرطي (صفه) نحاسي اللون, نحاسي
עברית (Hebrew)
n. - נחושת, מטבע, פרפר שכנפיו כצבע הנחושת
v. tr. - ציפה בנחושת
n. - דוד-הרתחה, שוטר
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