|Boiling Point: 2840°K, 2567°C, 4653°F
Melting Point: 1357.75°K, 1084.6°C, 1984.3°F
Electrons Energy Level: 2, 8, 18, 1
Isotopes: 26 + 2 Stable
Heat of Vaporization: 300.3 kJ/mol
Heat of Fusion: 13.05 kJ/mol
Density: 8.96 g/cm3 @ 300°K
Specific Heat: 0.38 J/g°K
Atomic Radius: 1.57Å
Ionic Radius: 0.73Å
Electronegativity: 1.9 (Pauling); 1.75 (Allrod Rochow)
Vapor Pressure: 0.0505 Pa @ 1084.6°C
1s2 2s2p6 3s2p6d10 4s1
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. Copper is found extensively in the Indus Valley Civilization by the 3rd millennium BC. 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 suggest he was involved in copper smelting. Brass, an alloy of zinc and copper, was known to the Greeks but first used extensively by the Romans.
Alchemical Symbol, Cuprum
There are copper and bronze artifacts from Sumarian 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. In the Americas production in the Old Copper Complex, located in present day Michigan and Wisconsin, was dated back to at least 6000 to 3000 BC.
In Greek times, the metal was known by the name chalkos (equivalent of Roman aes) and named after the copper mines at Chalcis in Euboea. This stem is often seen as referring to copper, notably in mineralogy. "Chalcopyrite" is copper pyrites. The word was applied to iron as well after its introduction, long before the coining of sideros, "sideros". The word for steel is caluy, clearly related to chalcos. Copper was a very important resource for the Romans and Greeks.
Additional Representation of Alchemical Symbols for Copper
In Roman times, it became known as cyprium aes, "brass from Cyprus" or "brass of Venus" (aes being the generic term for copper alloys such as bronze-brass 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. The Venusian name stuck in the West, and gave us cobre in Spanish, cuivre in French and Kupfer in German. In Welsh it is copr, which suggests that this word comes from old Celtic, and is unassociated with Venus. The Phoenicians, and others, worked copper mines and smelters in Cyprus, Kupris. Venus, or Aphrodite, the Kupris, was born there, always loved the island, and was its patron. She is very often referred to as Cypris. The word "cuprium" could have come either from the island or the goddess, and it is impossible to make a distinction. The word cuprum was probably later Latin, and gave us the chemical symbol Cu. The Phoenicians were surely the ones who spread the knowledge and use of copper around the Mediterranean, and their metallurgical procedures were probably kept secret. Our word "copper" comes from the Plattdeutsch coper or koper, still used in Dutch.
In alchemy the symbol for copper was also the symbol for the planet Venus
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 BC) 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 BC, it was developed in China before 2800 BC, in the Andes around 2000 BC, in Central America around 600 AD, and in West Africa around 900 AD.
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.
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 in the following locations, among others: Great Orme in North Wales, Alderley Edge in Cheshire, the Isle of Man between England and Northern Ireland, Parys Mountain of Anglesey, and Ecton Mine in the Stafforshire Moorlands.
At Great Orme in North Wales, such working extended for a depth of 70 meters. At Alderley Edge in Cheshire, carbon dates have established mining at around 2280 - 1890 BC (at 95% probability).
Copper mining in United States began with marginal workings by Native Americans and some development by early Spaniards. Europeans were mining copper in Connecticut as early as 1709. Westward movement also brought an expansion of copper exploitation with developments of significant deposits in Michigan and Arizona during the 1850's and then in Montana during the 1860's.
Copper was mined extensively in Michigan's Keweenaw Peninsula with the heart of extraction at the productive Quincy Mine. Arizona had many notable deposits including the Copper Queen in Bisbee and the United Verde in Jerome. The Anaconda in Butte, Montana became the nation's chief copper supplier by 1886.
Copper has also been mined at the Bingham Copper Mine near Salt Lake City, Utah as well as mines in Nevada and Tennessee.
Copper is a reddish-colored metal, with a high electrical and thermal conductivity (silver is the only pure metal to have a higher electrical conductivity at room temperature). In oxidation copper is mildly basic. 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. This can be contrasted with the optical properties of silver, gold and aluminum.
Copper exists as a metallically bonded substance, allowing it to have a wide variety of metallic properties.
Copper occupies the same family of the periodic table as silver and gold, since they each have one S-orbital electron on top of a filled shell. This similarity in electron structure makes them similar in many characteristics. All have very high thermal and electrical conductivity, and all are malleable metals.
In its liquid state, a clear copper surface without ambient light appears somewhat greenish, another characteristic shared with gold. Silver does not have this property, so it is not a complementary color for the orange incandescence color. When liquid copper is in bright ambient light, it retains some of its pinkish luster. Due to its high surface tension, the liquid metal does not wet surfaces but instead forms spherical droplets when poured on a surface.
Copper is insoluble in water (H2O) as well as in isopropanol.
Numerous copper alloys exist, many with important historical and contemporary uses. Speculum metal and bronze are alloys of copper and tin. Brass is an alloy of copper and zinc. Monel metal, also called cupronickel, is an alloy of copper and nickel. 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.
The purity of copper is expressed as 4N for 99.99% pure or 7N for 99.99999% pure. The numeral gives the number of nines after the decimal point when expressed as a decimal (eg 4N means 0.9999, or 99.99%).
The main copper ore producing countries are Chile, United States, Indonesia, Australia, Peru, Russia, Canada, China, Poland, Kazakhstan, Zambia and Mexico.
Copper can be found as native copper in mineral form. Minerals such as the sulfides: chalcopyrite (CuFeS2), bornite (Cu5FeS4), covellite (CuS), chalcocite (Cu2S) are sources of copper, as are the carbonates: asurite (Cu3(CO3)2(OH)2) and malachite (Cu2CO3(OH)2) and the oxide: cuprite (Cu2O).
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 began to drop steadily, most recently dropping to around $2.20.
Copper is malleable and ductile, a good conductor of heat and, and, when very pure, a good conductor of electricity.
The two most familiar alloys of copper are bronze and brass. Bronze, the first alloy created by people, is a mix of copper that contains as much as 25% tin. Early people used bronze to make tools, weaponry, containers and ornamental items. Brass, a mix of copper that contains between 5% and 45% zinc, was first used about 2,500 years ago. The Romans were the first to make extensive use of brass, using it to make such things as coins, kettles and ornamental objects. Today, brass is also used in some musical instruments, screws and other hardware that must resist corrosion.
It is used extensively, in products such as:
Copper is essential in all higher plants and animals. Copper is carried mostly in the bloodstream on a plasma proten 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, 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 mollusks and some arthropods 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 mgg/day. Because of its role in facilitating iron uptake, copper deficiency can often produce anemia like symptoms.
Hydrated copper sulfate (CuSO4·H2O), also known as blue vitrol, is the best known copper compound. It is used as an agricultural poison, as an algicide in water purification and as a blue pigment for inks. Cupric chloride (CuCl2), another copper compound, is used to fix dyes to fabrics. Cuprous chloride (CuCl) is a poisonous white powder that is chiefly used to absorb carbon dioxide (CO2). Copper cyanide (CuCN) is commonly used in electroplating.
Common oxidation states of copper include the less stable copper (I) state, Cu+; and the more stable copper (II) state, Cu2+, which forms blue or blue-green salts and solutions. Under unusual conditions, a +3 state and even an extremely rare +4 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 pentahydrate 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-d) or YBCO which forms the basis of many unconventional superconductors.
Copper (I) and Copper (II) can also be referred to by their common names cuprous and cupric.
Test for Copper (II) Ions
Add aqueous sodium hydroxide. A blue precipitate of copper (II) hydroxide should form.
Cu2+(aq) + 2OH-(aq) Cu(OH)2(s)
The full equation shows that the reaction is due to hydroxide ions deprotonating the hexaaquacopper (II) complex:
[Cu(H2O)6]2+(aq) + 2OH-(aq) Cu(H2O)4(OH)2(s) + 2 H2O(l)
Adding aqueous ammonia causes the same precipitate to form. It then dissolves upon adding excess ammonia, to form a deep blue ammonia complex, tetraamminecopper (II).
Cu(H2O)4(OH)2(s) + 4NH3(aq) [Cu(H2O)2(NH3)4]2+(aq) + 4H2O (l)
A more delicate test than the ammonia is the ferrocyanide of potassium, which gives a brown precipitate with copper salts.
|Cuprite, CuO2||Tenorite, CuO|
|Malachite, CuO3·Cu(OH)2||Chalcocite, Cu2S|
|Covellite, CuS||Bornite, Cu6FeS4|
|Azurite, Cu3(CO3)2(OH)2||Chalcopyrite, CuFeS2|
|Blue Vitriol, Copper Sulfate, CuSO4·5H2O|
|Copper (I) Chloride, Cuprous Chloride, CuCl|
|Copper (II) Chloride, Cupric Chloride, CuCl2|
Cuprous oxide, Cu2O is red, and cuprous sulphide, Cu2S is black. Both are very insoluble. In any soluble cuprous compound, auto-oxidation generally occurs, 2Cu+ Cu + Cu++, producing the cupric salt. Cupric oxide, CuO is produced by heating copper in air, or by strongly heating any oxygen-containing cupric salt. CuS is produced in an analogous way. In solution, the copper ion forms complex ions, such as Cu(H2O)4++, or Cu(NH3)4++. These are flat, square ions, of blue color. The water ion is medium blue, the ammonia ion dark blue.
Cupric sulphate, CuSO4·5H2O, called bluestone or blue vitriol, is soluble in 0°C water to 24.3%, in 100°C water to 205%. The blue color requires the water. The anhydrous salt, prepared by heating, is white or pale green. Its solutions are slightly acidic, and are strong germicides and fungicides. Bordeaux mixture is a garden insecticide that contains copper sulphate. The triclinic crystals are easily grown. This is the substance that supplies the copper ions in a Daniell cell or gravity cell. The sulphate can be recovered by dissolving the copper cathodes of the cells in sulphuric acid, so the copper is continuously regenerated as the zinc is burned.
The primary ores are sulphides and oxides, usually mixed with iron. Chalcocite is Cu2S, chalcopyrite CuFeS2, covellite CuS, and bornite Cu3FeS3. The oxides are cuprite Cu2O, tenorite CuO, malachite CuCO3·Cu(OH)2 (mineral verdigris), azurite 2CuCO3·Cu(OH)2, and the silicate chrysocolla CuSiO3·2H2O. Many of these minerals make attractive specimens, because of their green and blue colors, and can be carved into ornaments. They are not seen as crystals or massive forms in the ore mined today, but widely disseminated in an earthy matrix.
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.
|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 haemopoisesis.
Symptoms of copper poisoning are very similar to those produced by arsenic. Coppery eructations and taste. Fatal cases are generally terminated by convulsions, palsy, and insensibility.
In cases of suspected copper poisoning, Ovalbumin is to be administered in either of its forms which can be most readily obtained, as milk or whites of eggs. Vinegar should not be given. The inflammatory symptoms are to be treated on general principles, and so are the nervous.
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 bilel. 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.
Too much copper in water has also been found to damage marine life. The observed effect of these higher concentrations on fish and other creatures is damage to gills, liver, kidneys, and the nervous system. It also interferes with the sense of smell in fish, thus preventing them from choosing good mates or finding their way to mating areas.
|The metal, when powdered, is a fire hazard. At concentrations higher than 1 mg/L, copper can stain clothes and items washed in water.|
|Ionization Energy: 7.726 eV
Estimated Crustal Abundance: 6.0×10-1 milligrams per kilogram
Estimated Oceanic Abundance: 2.5×10-4 milligrams per liter