, as a result of its superior heat dissipation capacity to aluminium.
Bacteria will not grow on a copper surface because it is biostatic. Copper doorknobs
are used by hospitals to reduce the transfer of disease, and Legionnaire’s Disease is suppressed by copper tubing in air-conditioning systems.
Copper, as native copper, is one of the few metals to naturally occur as an uncompounded mineral. 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 compounds such as malachite or azurite. Among archaeological sites in Anatolia, Catal Hoyuk (~6000 BC) features native copper artifacts and smelted lead beads, but no smelted copper. But Can Hasan (~5000 BCE) had access to smelted copper; this site has yielded the oldest known cast copper artifact, a copper mace head.
Copper smelting appears to have been developed independently in several parts of the world. In addition to its development in Anatolia by 5000 BCE, it was developed in China before 2800 BCE, in the Andes around 2000 BCE, in Central America around 600 AD, and in West Africa around 900 AD. Copper is found extensively in the Indus Valley Civilization by the 3rd millennium BC. In Europe, Otzi 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 suggest he was involved in copper smelting. There are copper and bronze artifacts from Sumerian cities that date to 3000 BC, and Egyptian artifacts of copper and copper-tin alloys 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. In the Americas production in the Old Copper Complex, located in present day Michigan and Wisconsin, was dated back to between 6000 to 3000 BC.
The use of bronze became 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 (“copper-stone”), with some high-purity copper tools being used alongside stone tools. Brass was known to the Greeks, but only became a significant supplement to bronze during the Roman empire.
In Greek the metal was known by the name chalkos. Copper was a very important resource for the Romans, Greeks and other ancient peoples. 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.
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 enzymes.
Copper is a very interesting element. It is one of the transition elements that actually uses electrons from one of the inner orbitals in chemical reactions. In addition, it has more than one oxidation state. Like many of the transition elements, copper has a coloured ion. Copper typically forms a bluish green solution. Copper (Cu) has two valences Cu I (cuprous) has one valence electron and Cu II (cupric) has two valence electrons. Copper was one of the earliest known metals, having reportedly been mined for over 5000 years. In nature it has two isotopes, 63 (69.09%), which has 29 electrons and protons and 34 neutrons, and 65 (30.91%), which has 29 electrons and protons and 36 neutrons. Brass and bronze are alloys of copper.
When powdered, the metal is a fire hazard (may react explosively with strong oxidizing agents), it may also cause respiratory irritation. All copper compounds are toxic. Thirty grams of copper sulfate is potentially lethal in humans.
Bismuth strontium calcium copper oxide Bi2Sr2CanCun+1O2n+6
A family of high-temperature superconductors and also the first high-temperature superconductors to be discovered which did not contain a rare earth element.
Copper gluconate C12H22CuO14
Dietary supplement — metabolizable copper to treat copper deficiency. Used to treat acne vulgaris, common cold, hypertension, premature labor, Leishmaniasis, visceral postoperative complications.
Copper(II) arsenate Cu3(AsO4)2.4H2O or Cu5H2(AsO4)4.2H2O
Is an insecticide used in agriculture, also used as a herbicide, fungicide, and a rodenticide.
Copper(II) bromide CuBr2
It is used in photographic processing as an intensifier and as a brominating agent in organic synthesis.
It is also used in the copper vapour laser, a class of laser where the medium is copper bromide vapour formed in situ from hydrogen bromide in reaction with the enclosing copper discharge tube.  Producing yellow or green light, it is used in dermatological applications.
Copper indium gallium selenide (CIGS) Cu(Ga,In)Se2
CIGS is a new semiconductor used mainly in photovoltaic cells (CIGS cells).
CIGS solar cells are not as efficient as crystalline silicon solar cells, but they are expected to be substantially cheaper. CIGS can be printed directly onto molybdenum coated glass sheets. Solar cells made from crystalline silicon are made of slices of solid silicon and require therefore more expensive semiconductor material.
Copper(II) sulfate CuSO4.5H2O
It can be used to plate metals with copper, as a fungicide or herbicide, or as a chemical test for water (the anhydrous form will absorb water, turning blue).
Copper sulfate is also used to test blood for anemia. A drop of the patient’s blood is dropped into a container of copper sulfate, if it sinks within a certain time, then the patient has sufficient haemogloblin levels and is not anemic. If the blood floats or sinks too slowly, then the patient is iron-deficient and may be anemic.
It commonly occurs by the action of acetic acid when copper, brass or bronze is weathered and exposed to air or seawater over a period of time. Its name comes from the Middle English vertegrez, from the Old French verte grez, an alteration of vert-de-Grice – verd (green), de (of), and Grice (Greece)- “green of Greece”.
The vivid green colour of verdigris makes it a very common pigment. Until the 19th century, verdigris was the most vibrant green pigment available and frequently used in painting. Verdigris is lightfast in oil paint, as numerous examples of 15th century paintings show. However, its lightfastness and air resistance is very low in other media. Copper resinate, made from verdigris, is not lightfast, even in oil paint. In the presence of light and air, green copper resinate becomes stable brown copper oxide.
Reactions of Copper
Reactions with air
Copper metal is stable in air under normal conditions. When red hot, copper metal and oxygen react to form Cu2
4Cu(s) + O2(g) –> 2Cu2O(s)
Reactions with halogens
Copper reacts with fluorine, chlorine and bromine to form copper(II) dihalides.
Cu(s) + F2(g) –> CuF2(s)
Cu(s) + Cl2(g) –> CuCl2(s)
Cu(s) + Br2(g) –> CuBr2(s)
Reactions with acids
Copper metal dissolves in hot concentrated sulphuric acid to form solutions containing the aquated Cu(II) ion together with hydrogen gas.
Cu(s) + H2SO4(aq) –> SO42-(aq) + H2(g)
Copper metal also dissolves in dilute or concentrated nitric acid.
Occurrence of Copper
In 2005, Chile was the top mine producer of copper with atleast one-third world share followed by the USA, Indonesia and Peru, reports the British Geological Survey.
Copper can be found as native copper in mineral form. Minerals such as the sulfides: chalcopyrite
S) are sources of copper, as are the carbonates: azurite
) and malachite
) and the oxide: cuprite
Most copper ore is mined or extracted as copper sulfides from large open pit mines in porphyry copper deposits that contain 0.4 to 1.0 percent copper. Examples include: Chuquicamata 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 quintupled since 1999, rising from $0.60 per pound in June 1999 to $3.75 per pound in May 2006, where it dropped to $2.40 in February 2007 then rebounded to $3.50 in April 2007.
Isotopes of Copper
63Cu [34 neutrons]
Stable with 34 neutrons
65Cu [36 neutrons]
Stable with 36 neutrons