Copper: Structure, Functions and Chemistry

Copper: Structure, Functions and Chemistry COPPER (I) Copper has played a significant role in the history of human civilization, he was the first metal produced on a larger scale and used for practical purposes. Copper has been used by humans since ancient times, in the oldest antiquity and almost certainly soon after gold and argint. Archeologists discovered objects of this metal dating from 8700 BC, the occurrence of copper, much tougher and cheaper than gold and argint, expand the uses and the manufacture of weapons and various utensils (especially plows), thus making a significant jump in history: the transition from the Stone Age to the Bronze Age. Copper is one of the chemical elements of the base, a metal which pure has orange-red color and has a high electrical and thermal conductivity. Distinctive color of the copper, reddish, has made as first people to use him in creating jewelry and tools. Currently it is used to create a variety of products (cables, cooking pots and pans, tubes and pipes, car radiators, etc..), and pigm ent and preservative for paper, paint, textile and wood. Can also be used in various combinations, with zinc produce brass and with tin produces bronze . In the Earths crust, copper reserves are estimated to be about 70 parts per million, which puts them among the top four of the Earth reserves. Copper is found in its natural state, but most are in the mineral reserves, of which the most important are chalcopyrite and bornite. From the point of view of the spread in nature, copper may be found either in the native form (pure or bonded) or be in the form of compounds or minerals. After existing information, the copper was discovered in the year 6000 BC, by a people living in Turkestan or on the southern slope of the Caucasus. From here emerged in Mesopotamia, Egypt, Crete and eventually in Europe. Judging after the old copper objects found, it can be said that this metal has emerged in Egypt 5,000 years BC and then, after a millennium, in the region between the Tigris and Euphrates, where the Sumerian civilization developed. In Egypt, on the pharaoh time Turmes, the copper was exploited in Sinai Peninsula and was known as Komt. Copper ores used by ancient peoples came from Asia Minor and the Cypru. Also, the great philosopher of antiquity, Aristotle (330 BC) wrote that in India there is a kind of copper that can not distinguish gold than by weight (it been easier). The first large deposits of copper ore were discovered about 3000 BC, in the island of Cyprus in the Mediterranean.There is evidence that the Greeks and then the Romans extracted copper from Cyprus (since 1500 BC). When the Romans conquered Cyprus, the Romans brought copper almost entirely from Cyprus, so they called him, Cyprium, metal of Cyprus, then shortened to cyprium and later at cuprum. In South America, the findings showed that there were copper objects from 500 BC along the north coast of Peru. A development in copper processing was done when the Inca empire fell, it being conquered by the Spanish in the 1500s. Regarding the United States, the first copper mine is known in Connecticut (Branby) in 1705, followed by Pennsylvania (Lancaster) in 1732. However, production of copper objects was based on copper imported from Chile until 1844, when were discovered large deposits of copper ore, high quality, around Lake Superior. With the development of techniques for processing by the late 1800s, began exploiting the copper ore lower quality in large mines open in the western United States. The biggest piece of elemental copper found in nature weighed 420 tonnes and was found in 1857 in the Keweenaw Peninsula of Michigan, USA. Copper-containing minerals, such as chalcopyrite, Azurite, malachite, copper is present in the earths crust at a concentration of 50 parts per million, and constituted 0.01% of the. Most of copper removed from the mine is in the form of compounds such as sulfides or sulfates. Today, copper ores (copper sulfides, oxides and carbonates) are found in the USA and Canada, as well as several other places (in more than 50 nations). Should be noted, however, about half of the amount of copper in the world comes dinChile and the United States. New Mexico, Nevada, and Montana are states that give the largest amount of copper (about 98 percent) in the United States. World production of copper is about 12 million tons per year and the reserves are about 300 million tons, and is projected to be only for another 25 years. Strongest copper manufacturers, top two are United States and Chile, followed by Canada, Peru, Australia, Russia, China and Indonesia. About 2 million tons of copper per year are recovered through recycling process. With 2000 years BC, the copper was used only in the manufacture of bronze, and later on making some ornaments and copper combinations of coloring glass in blue (used as a precious stone, rings, brooches and so on). Objects of copper with the greatest seniority were found in areas with historical significance, eg Chaldea, Egypt, Assyria, Phoenicia and America. Thus the oldest objects found in northern Iraq, beads native copper (nuggets), dating from about 9000 BC, and various tools for processing of copper, made in about 5000 BC. In the New World copper objects were used by Native Americans as early as 2000 BC. In China was used to create bells. Later, the copper has been widely used in various alloys as bronze and brass (copper zinc) Èâ„ ¢i copper tin zinc. As bronze, was used to make cutlery, coins, tools, art and various bronze vessels. Copper alloys have been strong enough to be used in guns and cannons, and was known as †gun metal†. Homer wrote of weapons made of copper. Around the year 900 BCE, copper salts have been used for painting had expensive homes, being combined with clay and lime later. The alloy of copper and nickel (cupronickel) was the preferred metal for coins, bronze coins first appeared in Egypt, between 430-322 BC, and is now used this alloy for achieving U.S. coins. Because he was one of the main metals (together of gold and silver ), copper came to the attention of the alchemists, who called Venus, after the planet that regarded represented by copper. It is now widely used like bronze and brass in construction, truss building, roofing, heating and plumbing systems. Also, the copper is used heavily for electrical equipment (60%), almost every electrical device (electric clocks, stoves, portable CD players, and electricity transmission wires) is based on copper, because it has a high electrical conductivity and cheap. It is well known that older telephone lines were made à ¢Ã¢â€š ¬Ã¢â‚¬ ¹Ãƒ ¢Ã¢â€š ¬Ã¢â‚¬ ¹of thick copper wire packages, computers have copper circuit boards. Some copper alloys are used as pesticide for insects and rodents. Also, Copper alloys are found used in a variety of compounds: battery fluid, in fireproof, fabric paints, food additives for farm animals; fireworks (bright emerald color); The copper alloys underpin the manufacture of ceramics and enamels, photographic film, the different pigments and marine paints, as well as metals conservation, water purification, and wood protection. Using copper compounds, can also be undertaken and semi precious stones, such as turquoise (vary in color from green to blue) and malachite. Physical properties are usually those that can be observed using our senses such as color, luster, freezing point, boiling point, melting point, density, hardness and odor. A disc of copper (99.95% pure) In its solid state, of metal, copper has with a face-centered cubic crystalline structure, and is reddish, this color is the main property after which differs from the other elements. Copper color reflects red and orange light and absorbs other frequencies in the visible spectrum, due to its band structure. The copper crystal (cubic, face-centered) is lacking the presence of polymorphism. Usually, most of the inorganic compounds and organic compounds of copper are blue in color, although some may be green or greenish. Very interesting are his properties,to form compounds by green color (carbonate, chloride, etc.), Black (oxide) or blue (sulfate and hydroxide). One of the disadvantages of copper is the phenomenon of Cocle (greening), which can be often observed on old vessels and coins. Together with osmium (blue) and gold (golden yellow), the copper is one of three elemental metals has natural color other than gray or silver. Pure copper is orange-red and acquires a reddish stain when exposed to air, and will be green later. Cooper has a high melting point (1083 °C), which cause limited use to the pure metal. It can easily combine with other metals: Zn, Sn and Ni, forming alloys: brass, bronze,constantan, with improved properties and low melting points. He has a shine or glow, and his boiling point is 2595 °C. Its density is 8.96 grams per cubic centimeter. Copper is a very soft metal with a hardness of 3 on the Mohs scale (50 scale Vickers), tensile strength stood at 210 MPa, but is quite resistant to breaking, and very ductile (can be drawn into wires) and can be molded at high pressure. Both copper and its alloys have a very high pliability (can be drawn in thin sheets), and are very easy to process. However, the ductility of copper is extremely favorable, thus being able to obtain very thin copper wire, called strands (they used in the past, fuses). It is malleable, ductile, and an extremely good conductor of both heat and electricity. It is softer than zinc and can be polished to a bright finish . Is similar to the thermal conductivity of silver (silver 1 to 0.93), and much higher than other common metals. Precisely because of this property, copper pipe is used to transfer heat. However, the conductivity of copper is decreased when cooper is impure; when cooper contain the impurities of 0.1% of elements such as phosphorus, arsenic, silicon or iron, the conductivity may lower even by 20%. Therefore, electrotechnics uses only pure copper electrolyte. Like all metals, if copper is plated with another metal, begin galvanic corrosion process. Chemical properties Atomic number of copper is 29, and is found in group 11 of the periodic table, together with silver and gold, and has symbol Cu. Relative atomic mass is 63.546. The valence of copper is essentially 1 or 2 (a rare form copper compounds and salts of oxidation state 1, and 2, which are commonly called cuprous or cupric salts), although less may be even 3 . It is found in Group 11, Period 4 of the periodic table. Copper isotope 6429Cu electronic shell electron, 29 protons and 35 neutrons in the nucleus. Thanks to its electronic structure, copper may transfer an electron located on the last layer, forming ion CuI. Who ion combinations are stable. Copper can give, besides the electron located on the last layer, another electron, which is on the penultimate layer, forming ions CuII Copper does not react with water, but reacted slowly with the ambient air, as a result of this reaction, the copper surface to form a green layer of oxidized copper. In contrast to the oxidation of iron in moist air, this oxide layer stops the corrosion; a layer of green verdigris (copper carbonate) can be seen on old copper constructions, such as the Statue of Liberty, the largest copper statue world. Most copper salts are hygroscopic. Copper presents magnetic conductivity. Isotopes Copper has 29 isotopes; two of them, 63Cu and 65Cu are stable, and isotope 63Cu represents 69% of all natural copper. The other isotopes 27 are unstable (radioactive); the most stable of the radioactive is 67 Cu with half-life by 61.83 hours. Seven other isotopes have been characterized; between radioactive isotopes, it remark 63Cu, which emit positive beta radiation, resulting the isotopes of nickel, while the 65Cu isotope, with beta negative radioactive emissions, has results zinc isotopes. It should be noted that although it is a metal, copper is an essential element of life. It is found in all tissues of the body, but most of the copper found in the liver, and small quantities are found in the brain, heart, kidney and muscle. As beneficial effects, copper helps the body to use iron in the blood, reducing free radicals actions on tissues. Consuming foods copper may also prevent certain diseases or disabilities, such as allergies, baldness, AIDS, leukemia, osteoporosis and stomach ulcers. With iron (another metal), the copper assists in the synthesis of red blood cells. But it must be noted that copper does not break down in the environment, so it can be accumulated by plants and animals. This means that where there is copper in large quantities, it can develop only a limited number of plants, which adversely affect the work of agricultural land according to soil acidity and the presence of organic matter. However, manure containing large copper, is still applied on fields farm. Also, copper negatively influence activity of microorganisms and earthworms, which implies a slow decomposition of organic matter. Cupric salts are very powerful poisons for algae and fungi. Therefore, impregnate wood sulphate or copper naphthenate, to avoid the mushrooms and sprinkled vineyards, against blight, with a solution of copper sulphate mixed with lime. Copper has played a significant role in the history of human civilization, it the first metal produced on a larger scale and used for practical purposes. Copper is, after iron, the metal most used. After ones set, we find that the copper is a very common substance that occurs naturally in the environment and people use extensively. Apply in industry and agriculture, which made as à ¢Ã¢â€š ¬Ã¢â‚¬ ¹Ãƒ ¢Ã¢â€š ¬Ã¢â‚¬ ¹copper production to increase over the last decades.