Difference between revisions of "Copper" - New World Encyclopedia

From New World Encyclopedia
(→‎External links: deleted template for Wikimedia Commons)
Line 1: Line 1:
 
{{otheruses}}
 
{{otheruses}}
−
 
+
{{Elementbox_header | number=29 | symbol=Cu | name=copper | left=[[nickel]] | right=[[zinc]] | above=- | below=[[silver|Ag]] | color1={{Element color/Transition metals}} | color2=black }}
−
{{Elementbox_header | number=29 | symbol=Cu | name=copper | left=[[nickel]] | right=[[zinc]] | above=- | below=[[silver|Ag]] | color1=#ffc0c0 | color2=black }}
 
 
{{Elementbox_series | [[transition metal]]s }}
 
{{Elementbox_series | [[transition metal]]s }}
 
{{Elementbox_groupperiodblock | group=11 | period=4 | block=d }}
 
{{Elementbox_groupperiodblock | group=11 | period=4 | block=d }}
−
{{Elementbox_appearance_img | Cu,29|metallic brown}}
+
{{Elementbox_appearance_img | Cu,29|metallic brown}}
−
{{Elementbox_atomicmass_gpm | [[1 E-26 kg|63.546(3)]] }}
+
{{Elementbox_atomicmass_gpm | [[1 E-26 kg|63.546]][[List of elements by atomic mass|(3)]] }}
 
{{Elementbox_econfig | &#91;[[argon|Ar]]&#93; 3d<sup>10</sup> 4s<sup>1</sup> }}
 
{{Elementbox_econfig | &#91;[[argon|Ar]]&#93; 3d<sup>10</sup> 4s<sup>1</sup> }}
 
{{Elementbox_epershell | 2, 8, 18, 1 }}
 
{{Elementbox_epershell | 2, 8, 18, 1 }}
Line 18: Line 17:
 
{{Elementbox_heatcapacity_jpmolkat25 | 24.440 }}
 
{{Elementbox_heatcapacity_jpmolkat25 | 24.440 }}
 
{{Elementbox_vaporpressure_katpa | 1509 | 1661 | 1850 | 2089 | 2404 | 2836 | comment= }}
 
{{Elementbox_vaporpressure_katpa | 1509 | 1661 | 1850 | 2089 | 2404 | 2836 | comment= }}
−
{{Elementbox_section_atomicprop | color1=#ffc0c0 | color2=black }}
+
{{Elementbox_section_atomicprop | color1={{Element color/Transition metals}} | color2=black }}
 
{{Elementbox_crystalstruct | cubic face centered }}
 
{{Elementbox_crystalstruct | cubic face centered }}
 
{{Elementbox_oxistates | '''2''', 1<br />(mildly [[base (chemistry)|basic]] oxide) }}
 
{{Elementbox_oxistates | '''2''', 1<br />(mildly [[base (chemistry)|basic]] oxide) }}
 
{{Elementbox_electroneg_pauling | 1.90 }}
 
{{Elementbox_electroneg_pauling | 1.90 }}
 
{{Elementbox_ionizationenergies4 | 745.5 | 1957.9 | 3555 }}
 
{{Elementbox_ionizationenergies4 | 745.5 | 1957.9 | 3555 }}
−
{{Elementbox_atomicradius_pm | [[1 E-10 m|135]] }}
+
{{Elementbox_atomicradius_pm | [[1 E−10 m|135]] }}
−
{{Elementbox_atomicradiuscalc_pm | [[1 E-10 m|145]] }}
+
{{Elementbox_atomicradiuscalc_pm | [[1 E−10 m|145]] }}
−
{{Elementbox_covalentradius_pm | [[1 E-10 m|138]] }}
+
{{Elementbox_covalentradius_pm | [[1 E−10 m|138]] }}
 
{{Elementbox_vanderwaalsrad_pm | [[1 E-10 m|140]] }}
 
{{Elementbox_vanderwaalsrad_pm | [[1 E-10 m|140]] }}
−
{{Elementbox_section_miscellaneous | color1=#ffc0c0 | color2=black }}
+
{{Elementbox_section_miscellaneous | color1={{Element color/Transition metals}} | color2=black }}
 
{{Elementbox_magnetic | [[diamagnetism|diamagnetic]] }}
 
{{Elementbox_magnetic | [[diamagnetism|diamagnetic]] }}
 
{{Elementbox_eresist_ohmmat20 | 16.78 n}}
 
{{Elementbox_eresist_ohmmat20 | 16.78 n}}
Line 41: Line 40:
 
{{Elementbox_brinellhardness_mpa | 874 }}
 
{{Elementbox_brinellhardness_mpa | 874 }}
 
{{Elementbox_cas_number | 7440-50-8 }}
 
{{Elementbox_cas_number | 7440-50-8 }}
−
{{Elementbox_isotopes_begin | isotopesof=copper | color1=#ffc0c0 | color2=black }}
+
{{Elementbox_isotopes_begin | isotopesof=copper | color1={{Element color/Transition metals}} | color2=black }}
 
{{Elementbox_isotopes_stable | mn=63 | sym=Cu | na=69.17% | n=34 }}
 
{{Elementbox_isotopes_stable | mn=63 | sym=Cu | na=69.17% | n=34 }}
 
{{Elementbox_isotopes_stable | mn=65 | sym=Cu | na=30.83% | n=36 }}
 
{{Elementbox_isotopes_stable | mn=65 | sym=Cu | na=30.83% | n=36 }}
 
{{Elementbox_isotopes_end}}
 
{{Elementbox_isotopes_end}}
−
{{Elementbox_footer | color1=#ffc0c0 | color2=black }}
+
{{Elementbox_footer | color1={{Element color/Transition metals}} | color2=black }}
  
−
'''Copper''' is a [[chemical element]] in the [[periodic table]] that has the symbol '''Cu''' and [[atomic number]] 29.
+
'''Copper''' (symbol '''Cu''', from the [[Latin]] word ''cuprum''; [[atomic number]] 29) is a [[chemical element]] in the [[periodic table]]. 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.
  
 
== History ==
 
== History ==
−
In Greek times, the metal was known by the name ''chalkos'' (&#967;&#945;&#955;&#954;&#972;&#962;). 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 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 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 B.C.E. By 5000 B.C.E. 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 B.C.E.
+
[[Image:Copper Ingot Crete.jpg|left|thumb|150px|Ancient Copper [[ingot]] from [[Zakros]], [[Crete]] is shaped in the form of an animal skin typical for that era.]]
 +
 
 +
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 (goddess)|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 (planet)|Venus]].
 +
 
 +
[[Image:Copper-symbol.png|thumb|right|75px|Alchemical symbol for copper]]
 +
 
 +
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 B.C.E. By 5000 B.C.E., there are signs of copper [[smelting]], the refining of copper from simple copper compounds such as [[malachite]] or [[azurite]]. The oldest known cast copper object is a copper [[mace]] head, recovered from [[Can Hasan]] in southern Anatolia and dated to around 5000 B.C.E.  Copper was the first metal to be smelted from ores.[http://www.mindat.org/min-1209.html]The earliest signs of [[gold]] use, by contrast, appear around 4000 B.C.E.. There are copper and [[bronze]] artifacts from [[Sumer]]ian cities that date to 3000 B.C.E., and [[Ancient Egypt|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 B.C.E. By 1200 B.C.E. 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 B.C.E.]], 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 [[Ancient Greece|Greek]]s but first used extensively by the [[Ancient Rome|Romans]].
  
−
There are copper and [[bronze]] artifacts from [[Sumerian]] cities that date to 3000 B.C.E., and [[Ancient Egypt|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 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.
  
−
[[Image:Copper Ingot Crete.jpg|left|thumb|175px|Ancient Copper [[ingot]] from Zakros, Crete. The ingot is shaped in the form of an animal skin, a typical shape of copper ingots from these times.]]
+
==Notable characteristics==
  
−
The Egyptians found that adding a small amount of tin made the metal easier to cast, so bronze alloys are found in Egypt almost as soon as copper is found. Use of copper in ancient [[China]] dates to at least 2000 B.C.E.. By 1200 B.C.E. 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 B.C.E.]], 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.
+
Copper is a reddish [[metal]], with high [[electrical conductivity|electrical]] and thermal conductivity. (Among pure metals at room temperature, only [[silver]] has higher electrical conductivity). In [[oxidation]] is [[wikt:mildly|mildly]] [[Base (chemistry)|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]]. Contrast this with the optical properties of [[silver]], [[gold]], and [[aluminum]].
  
−
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 occupies the same family of the periodic table as silver and gold, hence it shares many characteristics with these metals. All have very high thermal and electrical conductivity. All are malleable metals. Gold and copper are the only colored metallic elements besides [[caesium]], the [[alkali metal]] of [[period]] six.
 +
 
 +
Copper is insoluble in water (H<sub>2</sub>O) as well as in isopropanol, or [[isopropyl alcohol]].
 +
 
 +
There are two stable isotopes, <sup>63</sup>Cu and <sup>65</sup>Cu, 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, <sup>64</sup>Cu, has a half life of 12.7 hours, with two decay modes, leading to two separate products.
 +
 
 +
There are numerous [[alloy]]s of copper&mdash;[[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 [[aluminium bronze]], silicon bronze, and manganese bronze.
 +
 
 +
The purity of copper is expressed as 4N for 99.9999% pure or 7N for 99.9999999% pure. The numeral gives the number of nines after the decimal point.
 +
 
 +
== Applications ==
 +
[[Image:Metallic bond Cu.svg|thumb|left|250px|Copper exists as a [[metallic bond|metallically bonded]] substance, allowing it to have a wide variety of metallic properties.]]
 +
Copper is [[malleable]] and [[ductile]], and is used extensively, in products such as:
 +
* Copper [[wire]].
 +
* Copper [[plumbing]].
 +
* Doorknobs and other fixtures in houses.
 +
* [[Statue|Statuary]]: The [[Statue of Liberty]], for example, contains 179,200 pounds (81.3 [[tonne]]s) of copper.
 +
* [[Roofing]], guttering, and rainspouts on buildings.
 +
* [[Electromagnet]]s.
 +
* [[Electrical machine]]s, especially electromagnetic motors and generators.
 +
* [[James Watt|Watt]]'s [[steam engine]].
 +
* Electrical [[relay]]s, electrical [[busbar]]s and electrical [[switch]]es.
 +
* [[Vacuum tube]]s, [[cathode ray tube]]s, and the [[magnetron]]s in [[microwave oven]]s.
 +
* [[Waveguide|Wave guide]]s for microwave radiation.
 +
* There is increasing use of copper in [[integrated circuit]]s, replacing [[aluminium]] because of its superior conductivity.
 +
* Alloyed with [[nickel]], e.g. [[cupronickel]] and [[Monel]], used as corrosive resistant materials in [[shipbuilding]].
 +
* As a component of [[coin]]s, often as cupronickel alloy.
 +
* In [[cookware]], such as [[frying pan]]s.
 +
* Most [[flatware]] ([[knife|knives]], [[fork]]s, [[spoon]]s) contains some copper ([[nickel silver]]).
 +
* [[Sterling silver]], if it is to be used in dinnerware, must contain a few percent copper.
 +
* As a component in ceramic [[glaze]]s, and to color [[glass]].
 +
* [[Musical instrument]]s, especially [[brass instrument]]s.
 +
* As a [[biostatic]] surface in hospitals, and to line parts of [[ship]]s to protect against [[barnacle]]s and [[mussel]]s, originally used pure, but superseded by [[Muntz Metal]]. [[Bacteria]] will not grow on a copper surface because it is biostatic. Copper [[doorknob]]s are used by [[hospital]]s to reduce the transfer of disease, and [[Legionnaire's Disease]] is suppressed by copper tubing in [[air-conditioning]] systems.
 +
* Compounds, such as [[Fehling's solution]], have applications in chemistry.
 +
* [[Copper(II) sulfate]] is used as a [[fungicide]] and as algae control in domestic lakes and ponds. It is used in gardening powders and sprays to kill [[mildew]].
 +
* As a material in the manufacture of computer [[heatsinks]], as a result of its superior heat dissipation capacity to [[aluminium]].
 +
* Copper was sometimes used by the [[Inuit]] to make the cutting blade for [[ulu]]'s.
 +
*[[Cent (United States coin)|U.S. Pennies]] are  2.5% copper by weight (Balance [[zinc]] 97.5%).
 +
*[[Nickel (United States coin)|U.S. Nickels]] are  75.0% copper by weight (Balance [[nickel]] 25.0%).
 +
*[[Dime (United States coin)|U.S. Dimes]] are    91.67% copper by weight (Balance [[nickel]] 8.33%).
 +
*[[Quarter (United States coin)|U.S. Quarters]] are 91.67% copper by weight (Balance [[nickel]] 8.33%).
 +
 
 +
[[Image:Minneapolis City Hall.JPG|thumb|left|200px|Copper roof on the [[Minneapolis City Hall]] ]]
  
−
[[Image:Copper-symbol.png|thumb|left|75px|Alchemical symbol for copper]]
 
  
−
[[Brass]], an [[alloy]] of [[zinc]] and copper, was known to the [[Ancient_Greece|Greek]]s but first used extensively by the [[Ancient Rome|Romans]].
 
  
−
Copper was associated with the goddess [[Aphrodite]]/[[Venus (goddess)|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 (planet)|Venus]].
 
  
 
== Biological role ==
 
== 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]], the Cu-Zn containing enzyme [[superoxide dismutase]], and is the central metal in the [[oxygen]] carrying pigment [[hemocyanin]]. The blood of the [[horseshoe crab]], ''Limulus polyphemus'' uses copper rather than [[iron]] for oxygen transport.
+
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 [[Recommended Dietary Allowance|RDA]] for copper in normal healthy adults is 0.9 [[milligram|mg]]/day.
 
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 [[Recommended Dietary Allowance|RDA]] for copper in normal healthy adults is 0.9 [[milligram|mg]]/day.
  
 
=== Toxicity ===
 
=== Toxicity ===
−
All copper compounds, unless otherwise known, should be treated as if they were [[toxic]]. 30g 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 [[Dietary Reference Intake|DRI]] Tolerable Upper Intake Level for adults of dietary copper from all sources is 10 mg/day.
+
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 [[Dietary Reference Intake|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's reagent|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.
  
−
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.
+
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.
  
 
=== Miscellaneous hazards ===
 
=== 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.
 
The metal, when powdered, is a [[fire hazard]]. At concentrations higher than 1 mg/L, copper can stain clothes and items washed in water.
  
−
== Physical characteristics ==
+
== Occurrence ==
−
[[Image:Cu,29.jpg|200px|left]]
+
[[Image:Chino copper mine.jpg|200px|left|thumb|[[El Chino Mine|El Chino]] open-pit copper mine in [[New Mexico]].]]
−
Copper is a reddish-coloured  [[metal]], with a high [[electrical conductivity|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]].
+
:''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]].
 +
.<ref>http://www.mii.org/Minerals/photocopper.html</ref>
 +
 
 +
Copper can be found as [[native copper]] in [[mineral]] form. Minerals such as the [[sulfide]]s: [[chalcopyrite]] (CuFeS<sub>2</sub>), [[bornite]] (Cu<sub>5</sub>FeS<sub>4</sub>), [[covellite]] (CuS), [[chalcocite]] (Cu<sub>2</sub>S) are sources of copper, as are the [[carbonate]]s: [[azurite]] (Cu<sub>3</sub>(CO<sub>3</sub>)<sub>2</sub>(OH)<sub>2</sub>) and [[malachite]] (Cu<sub>2</sub>CO<sub>3</sub>(OH)<sub>2</sub>) and the oxide: [[cuprite]] (Cu<sub>2</sub>O). Native copper also forms in uneconomic placer deposits.
 +
 
 +
Most copper [[ore]] is mined or [[copper extraction|extracted]] as copper sulfides from large [[open pit mine]]s 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 [[parts per million|ppm]] by mass, and 22 ppm by atoms.
 +
 
 +
[[Image:Coppernuggets.jpg|200px|right|thumb|Native Copper Placer Nuggets]]
 +
 
  
−
There are two stable isotopes, <sup>63</sup>Cu and <sup>65</sup>Cu, along with a couple dozen radioisotopes. The vast majority of radioisotopes have half lives on the order of minutes or less, the longest lived, <sup>64</sup>Cu, has a half life of 12.7 hours, with two decay modes, leading to two separate products.
+
The [[Intergovernmental Council of Copper Exporting Countries]] (CIPEC), defunct since 1992, once tried to play a similar role for copper as [[OPEC]] does for [[Petroleum|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]].
  
−
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]].
+
The copper price has quintupuled since 1999, rising from $0.60 per [[Pound (mass)|pound]] in June 1999 to $3.75 per pound in May 2006 [http://www.kitcometals.com/charts/copper_historical_large.html].
  
−
=== Compounds ===
+
== Compounds ==
 
[[Image:CopperMineralUSGOV.jpg|thumb|Native copper]]
 
[[Image:CopperMineralUSGOV.jpg|thumb|Native copper]]
−
Common oxidation states of copper include the less stable copper(I) state, Cu<sup>+1</sup>; and the more stable copper(II) state, Cu<sup>+2</sup>, which forms lovely blue or blue-green salts. Under unusual conditions, a +3 state can be obtained.
+
Common oxidation states of copper include the less stable copper(I) state, Cu<sup>1+</sup>; and the more stable copper(II) state, Cu<sup>2+</sup>, 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 penta[[hydrate]] which is perhaps the most familiar copper compound in the laboratory. It is used as a [[fungicide]], known as Bordeaux mixture.
  
−
[[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 Bordeau mixture.
+
There are two stable copper oxides, [[copper(II) oxide]] (CuO) and [[copper(I) oxide]] (Cu<sub>2</sub>O). Copper oxides are used to make [[yttrium]] [[barium]] copper oxide (YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7-δ</sub>) or [[YBCO]] which forms the basis of many [[unconventional superconductors]].
  
−
There are two stable copper oxides, [[copper(II) oxide]] (CuO) and [[copper(I) oxide]] (Cu<sub>2</sub>O).  Copper oxides are used to make [[yttrium]] [[barium]] copper oxide (YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7-&delta;</sub>) or [[YBCO]] which forms the basis of many [[unconventional superconductors]].
+
*'''Copper (I) compounds''' : [[copper(I) chloride]], [[copper(I) oxide]].
  
−
Other compounds : [[Copper(I) chloride]], [[copper(II) chloride]], [[copper(II) sulfide]].
+
*'''Copper (II) compounds''' : [[copper(II) carbonate]], [[copper(II) chloride]], [[copper(II) hydroxide]], [[copper(II) nitrate]], [[copper(II) oxide]], [[copper(II) sulfate]], [[copper(II) sulfide]].
  
−
=== Occurrence ===
+
*'''Copper (III) compounds''' , rare: potassium hexafluorocuprate (K<sub>3</sub>CuF<sub>6</sub>)
−
[[Image:Chino copper mine.jpg|200px|left|thumb|The El Chino open-pit copper mine in [[New Mexico]].]]
 
−
:''See [[Copper extraction]] for the main article.''
 
  
−
Copper can be found as [[native copper]] in [[mineral]] form. Minerals such as the [[carbonate]]s [[azurite]] (Cu<sub>3</sub>(CO<sub>3</sub>)<sub>2</sub>(OH)<sub>2</sub>) and [[malachite]] (Cu<sub>2</sub>CO<sub>3</sub>(OH)<sub>2</sub>) are sources of copper, as are [[sulfide]]s such as [[chalcopyrite]] (CuFeS<sub>2</sub>), [[bornite]] (Cu<sub>5</sub>FeS<sub>4</sub>), [[covellite]] (CuS), [[chalcocite]] (Cu<sub>2</sub>S) and oxides like [[cuprite]] (Cu<sub>2</sub>O).
+
*'''Copper (IV) compounds''' , extremely rare: caesium hexafluorocuprate (Cs<sub>2</sub>CuF<sub>6</sub>)
  
−
Most copper [[ore]] is mined or [[copper extraction|extracted]] from large [[open pit mine]]s in copper [[porphyry]] deposits that contain 0.4 to 1.0 percent copper. Examples include: [[Chuquicamata]] in [[Chile]] and [[El Chino mine]] in [[New Mexico]]. The average abundance of copper found within crustal rocks is approximately 68000 parts per billion by mass, and 22000 parts per billion by atoms.  
+
Copper (I) and Copper (II) can also be referred to by their common names cuprous and cupric.
  
−
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]].
+
{{seealso|:Category:Copper compounds}}
  
 
== Tests for copper<sup>2+</sup> ion ==
 
== Tests for copper<sup>2+</sup> ion ==
Line 116: Line 175:
 
Ionic equation:
 
Ionic equation:
  
−
:Cu<sup>2+</sup><sub>(aq)</sub> + 2OH<sup>-</sup><sub>(aq)</sub> -> Cu(OH)<sub>2 (s)</sub>
+
:Cu<sup>2+</sup><sub>(aq)</sub> + 2OH<sup>−</sup><sub>(aq)</sub> → Cu(OH)<sub>2 (s)</sub>
  
−
Add aqeuous [[ammonia]]. A precipitate should form, which then dissolves upon adding excess ammonia, to form an ammonia complex, tetraaminecopper(II).
+
Add aqeuous [[ammonia]]. A precipitate should form, which then dissolves upon adding excess ammonia, to form a deep blue ammonia complex, tetraaminecopper(II).
  
 
Ionic equation:
 
Ionic equation:
  
−
:Cu<sup>2+</sup><sub>(aq)</sub> + 4NH<sub>3 (aq)</sub> -> Cu(NH<sub>3</sub>)<sub>4</sub><sup>2+</sup><sub>(aq)</sub>
+
:Cu<sup>2+</sup><sub>(aq)</sub> + 4NH<sub>3 (aq)</sub> → Cu(NH<sub>3</sub>)<sub>4</sub><sup>2+</sup><sub>(aq)</sub>
  
−
== Applications ==
 
−
Copper is [[malleable]] and [[ductile]], and is used extensively, in products such as:
 
  
−
* Copper [[wire]].
 
−
* Copper [[plumbing]].
 
−
* Doorknobs and other fixtures in houses.
 
−
* [[Statue|Statuary]]: The [[Statue of Liberty]], for example, contains 179,200 pounds (81.3 [[tonne]]s) of copper.
 
−
* [[Electromagnet]]s.
 
−
* [[Motor]]s, especially electromagnetic motors.
 
−
* [[James Watt|Watt]]'s [[steam engine]].
 
−
* Electrical [[relay]]s, electrical [[busbar]]s and electrical [[switch]]es.
 
−
* [[Vacuum tube]]s, [[cathode ray tube]]s, and the [[magnetron]]s in [[microwave oven]]s.
 
−
* [[Waveguide|Wave guide]]s for microwave radiation.
 
−
* There is increasing use of copper in [[integrated circuit]]s, replacing [[aluminium]] because of its superior conductivity.
 
−
* Alloyed with [[nickel]], e.g. [[cupronickel]] and [[Monel]], used as corrosive resistant materials in [[shipbuilding]].
 
−
* As a component of [[coin]]s, often as cupronickel alloy.
 
−
* In [[cookware]], such as [[frying pan]]s.
 
−
* Most [[flatware]] ([[knife|knives]], [[fork]]s, [[spoon]]s) contains some copper ([[nickel silver]]).
 
−
* [[Sterling silver]], if it is to be used in dinnerware, must contain a few percent copper.
 
−
* As a component in ceramic [[glaze]]s, and to color [[glass]].
 
−
* [[Musical instrument]]s, especially [[brass instrument]]s.
 
−
* As a [[biostatic]] surface in hospitals, and to line parts of [[ship]]s to protect against [[barnacle]]s and [[mussel]]s, originally used pure, but superceded by [[Muntz Metal]]. [[Bacteria]] will not grow on a copper surface because it is biostatic. Copper [[doorknob]]s are used by [[hospital]]s to reduce the transfer of disease, and [[Legionnaire's Disease]] is supressed by copper tubing in [[air-conditioning]] systems.
 
−
* Compounds, such as [[Fehling's solution]], have applications in chemistry.
 
−
* [[Copper(II) sulfate]] is used as a poison and a water purifier.  It is used in gardening powders and sprays to kill [[mildew]].
 
  
 
==References==
 
==References==
 
*[http://periodic.lanl.gov/elements/29.html Los Alamos National Laboratory - Copper]
 
*[http://periodic.lanl.gov/elements/29.html Los Alamos National Laboratory - Copper]
 
*''Copper: Technology & Competitiveness (Summary)'' Chapter 6: Copper Production Technology; Author: Office of Technology Assessment 2005
 
*''Copper: Technology & Competitiveness (Summary)'' Chapter 6: Copper Production Technology; Author: Office of Technology Assessment 2005
 +
*[http://www.ocean.udel.edu/horseshoecrab/funFacts.html NOAA and Univ. of Delaware, ''Horseshoe Crab Fun Facts''] Accessed 12-12-2005.
 +
*[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8619019&dopt=Abstract Radiat Res. 1996 May;145(5):542-53. Role of Fenton chemistry in thiol-induced toxicity and apoptosis.]
 +
*Current Medicinal Chemistry, Volume 12, Number 10, May 2005, pp. 1161-1208(48) Metals, Toxicity and Oxidative Stress
  
−
== External links ==
+
<references/>
−
*[http://www.webelements.com/webelements/elements/text/Cu/index.html WebElements.com &ndash; Copper]
+
 
−
*[http://www.healingedge.net/briefs_copper_tox.html Copper Toxicity Syndrome]
+
==External links==
−
*[http://www.best-home-remedies.com/minerals/copper.htm Copper- Benefits, Deficiency Symptoms And Food Sources]
+
{{Commons|Copper}}
−
*[http://www.copper.org/ The Copper Page]
+
{{wiktionary|copper}}
−
*[http://y2u.co.uk/&002_Images/Parys_Mountain_01.htm Photos of the Parys Mountain Copper Mine near Amlwch, Anglesey, Wales]
+
*[http://www.npi.gov.au/database/substance-info/profiles/27.html National Pollutant Inventory - Copper and compounds fact sheet]
−
*[http://www.gindre.com/cours_du_cuivre/l_home.htm Current copper price] as at June 2005, about USD$3,500 / tonne.
 
−
*[http://www.indexmundi.com/en/commodities/minerals/copper/copper_t20.html World mine production of copper by country]
 
  
 
[[Category:Physical sciences]]
 
[[Category:Physical sciences]]
 
[[Category:Chemistry]]
 
[[Category:Chemistry]]
 
[[Category:Chemical elements]]
 
[[Category:Chemical elements]]
−
[[Category:Transition metals]]
 
−
 
−
<!-- interwiki —>
 
−
 
−
[[af:Koper]]
 
−
[[bg:Мед]]
 
−
[[ca:Coure]]
 
−
[[cs:Měď]]
 
−
[[cy:Copr]]
 
−
[[da:Kobber]]
 
−
[[de:Kupfer]]
 
−
[[et:Vask]]
 
−
[[es:Cobre]]
 
−
[[eo:Kupro]]
 
−
[[fa:مس (فلز)]]
 
−
[[fr:Cuivre]]
 
−
[[ko:구리]]
 
−
[[hr:Bakar]]
 
−
[[io:Kupro]]
 
−
[[is:Kopar]]
 
−
[[it:Rame]]
 
−
[[he:נחושת]]
 
−
[[kw:Kober]]
 
−
[[ku:Sifir]]
 
−
[[la:Cuprum]]
 
−
[[lv:Varš]]
 
−
[[lt:Varis]]
 
−
[[hu:Réz]]
 
−
[[mk:Бакар]]
 
−
[[mi:Konukura]]
 
−
[[nl:Koper (element)]]
 
−
[[nds:Kopper]]
 
−
[[ja:銅]]
 
−
[[no:Kobber]]
 
−
[[nn:Kopar]]
 
−
[[oc:Coire]]
 
−
[[pl:Miedź]]
 
−
[[pt:Cobre]]
 
−
[[ro:Cupru]]
 
−
[[ru:Медь]]
 
−
[[simple:Copper]]
 
−
[[sl:Baker]]
 
−
[[sr:Бакар (хемијски елемент)]]
 
−
[[fi:Kupari]]
 
−
[[sv:Koppar]]
 
−
[[th:ทองแดง]]
 
−
[[vi:Đồng (nguyên tố)]]
 
−
[[tr:Bakır]]
 
−
[[uk:Мідь]]
 
−
[[zh:铜]]
 
  
−
{{credit|27211312}}
+
{{credit|65627566}}

Revision as of 21:56, 24 July 2006

For other uses, see Copper (disambiguation).
29 nickel ← copper → zinc
-
↑
Cu
↓
Ag
Cu-TableImage.png
periodic table
General
Name, Symbol, Number copper, Cu, 29
Chemical series transition metals
Group, Period, Block 11, 4, d
Appearance metallic brown
Cu,29.jpg
Atomic mass 63.546(3) g/mol
Electron configuration [Ar] 3d10 4s1
Electrons per shell 2, 8, 18, 1
Physical properties
Phase solid
Density (near r.t.) 8.96 g/cm³
Liquid density at m.p. 8.02 g/cm³
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
Heat of vaporization 300.4 kJ/mol
Heat capacity (25 °C) 24.440 J/(mol·K)
Vapor pressure
P/Pa 1 10 100 1 k 10 k 100 k
at T/K 1509 1661 1850 2089 2404 2836
Atomic properties
Crystal structure cubic face centered
Oxidation states 2, 1
(mildly basic oxide)
Electronegativity 1.90 (Pauling scale)
Ionization energies
(more) 		1st: 745.5 kJ/mol
2nd: 1957.9 kJ/mol
3rd: 3555 kJ/mol
Atomic radius 135 pm
Atomic radius (calc.) 145 pm
Covalent radius 138 pm
Van der Waals radius 140 pm
Miscellaneous
Magnetic ordering diamagnetic
Electrical resistivity (20 °C) 16.78 nΩ·m
Thermal conductivity (300 K) 401 W/(m·K)
Thermal expansion (25 °C) 16.5 µm/(m·K)
Speed of sound (thin rod) (r.t.) (annealed)
3810 m/s
Speed of sound (thin rod) (r.t.) 130 m/s
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
Notable isotopes
Main article: Isotopes of copper
iso NA half-life DM DE (MeV) DP
63Cu 69.17% Cu is stable with 34 neutrons
65Cu 30.83% Cu is stable with 36 neutrons

Copper (symbol Cu, from the Latin word cuprum; atomic number 29) is a chemical element in the periodic table. 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 alloys.

History

Ancient Copper ingot from Zakros, Crete is shaped in the form of an animal skin typical for that era.

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.

Alchemical symbol for copper

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 B.C.E. By 5000 B.C.E., there are signs of copper smelting, the refining of copper from simple copper compounds such as malachite or azurite. The oldest known cast copper object is a copper mace head, recovered from Can Hasan in southern Anatolia and dated to around 5000 B.C.E. Copper was the first metal to be smelted from ores.[1]The earliest signs of gold use, by contrast, appear around 4000 B.C.E. There are copper and bronze artifacts from Sumerian cities that date to 3000 B.C.E., 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 B.C.E. By 1200 B.C.E. 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 B.C.E., 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 Greeks 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.

Notable characteristics

Copper is a reddish metal, with high electrical and thermal conductivity. (Among pure metals at room temperature, only silver has higher electrical conductivity). In oxidation 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. Contrast this with the optical properties of silver, gold, and aluminum.

Copper occupies the same family of the periodic table as silver and gold, hence it shares many characteristics with these metals. All have very high thermal and electrical conductivity. All are malleable metals. Gold and copper are the only colored metallic elements besides caesium, the alkali metal of period six.

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 alloys of copper—speculum metal is a copper/tin alloy, brass is a copper/zinc alloy, and bronze is a copper/tin alloy. Monel metal is a copper/nickel alloy, also called cupronickel. While the metal "bronze" usually refers to copper/tin alloys, it also is a generic term for any alloy of copper, such as aluminium bronze, silicon bronze, and manganese bronze.

The purity of copper is expressed as 4N for 99.9999% pure or 7N for 99.9999999% pure. The numeral gives the number of nines after the decimal point.

Applications

Copper exists as a metallically bonded substance, allowing it to have a wide variety of metallic properties.

Copper is malleable and ductile, and is used extensively, in products such as:

  • Copper wire.
  • Copper plumbing.
  • Doorknobs and other fixtures in houses.
  • Statuary: The Statue of Liberty, for example, contains 179,200 pounds (81.3 tonnes) of copper.
  • Roofing, guttering, and rainspouts on buildings.
  • Electromagnets.
  • Electrical machines, especially electromagnetic motors and generators.
  • Watt's steam engine.
  • Electrical relays, electrical busbars and electrical switches.
  • Vacuum tubes, cathode ray tubes, and the magnetrons in microwave ovens.
  • Wave guides for microwave radiation.
  • There is increasing use of copper in integrated circuits, replacing aluminium because of its superior conductivity.
  • Alloyed with nickel, e.g. cupronickel and Monel, used as corrosive resistant materials in shipbuilding.
  • As a component of coins, often as cupronickel alloy.
  • In cookware, such as frying pans.
  • Most flatware (knives, forks, spoons) contains some copper (nickel silver).
  • Sterling silver, if it is to be used in dinnerware, must contain a few percent copper.
  • As a component in ceramic glazes, and to color glass.
  • Musical instruments, especially brass instruments.
  • As a biostatic surface in hospitals, and to line parts of ships to protect against barnacles and mussels, originally used pure, but superseded by Muntz Metal. 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.
  • Compounds, such as Fehling's solution, have applications in chemistry.
  • Copper(II) sulfate is used as a fungicide and as algae control in domestic lakes and ponds. It is used in gardening powders and sprays to kill mildew.
  • As a material in the manufacture of computer heatsinks, as a result of its superior heat dissipation capacity to aluminium.
  • Copper was sometimes used by the Inuit to make the cutting blade for ulu's.
  • U.S. Pennies are 2.5% copper by weight (Balance zinc 97.5%).
  • U.S. Nickels are 75.0% copper by weight (Balance nickel 25.0%).
  • U.S. Dimes are 91.67% copper by weight (Balance nickel 8.33%).
  • U.S. Quarters are 91.67% copper by weight (Balance nickel 8.33%).
File:Minneapolis City Hall.JPG
Copper roof on the Minneapolis City Hall


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 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 molluscs 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 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.

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.

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

El Chino open-pit copper mine in New Mexico.
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. .[1]

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: azurite (Cu3(CO3)2(OH)2) and malachite (Cu2CO3(OH)2) and the oxide: cuprite (Cu2O). Native copper also forms in uneconomic placer deposits.

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.

File:Coppernuggets.jpg
Native Copper Placer Nuggets


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 $3.75 per pound in May 2006 [2].

Compounds

Native copper

Common oxidation states of copper include the less stable copper(I) state, Cu1+; 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-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 (III) compounds , rare: potassium hexafluorocuprate (K3CuF6)
  • Copper (IV) compounds , extremely rare: caesium hexafluorocuprate (Cs2CuF6)

Copper (I) and Copper (II) can also be referred to by their common names cuprous and cupric.


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 a deep blue ammonia complex, tetraaminecopper(II).

Ionic equation:

Cu2+(aq) + 4NH3 (aq) → Cu(NH3)42+(aq)


References
ISBN links support NWE through referral fees

  1. ↑ http://www.mii.org/Minerals/photocopper.html

External links

Commons
Wikimedia Commons has media related to::

Credits

New World Encyclopedia writers and editors rewrote and completed the Wikipedia article in accordance with New World Encyclopedia standards. This article abides by terms of the Creative Commons CC-by-sa 3.0 License (CC-by-sa), which may be used and disseminated with proper attribution. Credit is due under the terms of this license that can reference both the New World Encyclopedia contributors and the selfless volunteer contributors of the Wikimedia Foundation. To cite this article click here for a list of acceptable citing formats.The history of earlier contributions by wikipedians is accessible to researchers here:

The history of this article since it was imported to New World Encyclopedia:

Note: Some restrictions may apply to use of individual images which are separately licensed.

Retrieved from https://www.newworldencyclopedia.org/p/index.php?title=Copper&oldid=78207

Content is available under Creative Commons Attribution/Share-Alike License; additional terms may apply. See Terms of Use for details.
Copyright Logo
Powered by MediaWiki