Engineering

Achieving ultra-low friction without oil additives

Researchers at Georgia Institute of Technology have developed a new process for treating metal surfaces that has the potential to improve efficiency in piston engines and a range of other equipment.

Energy & Green Tech

Longer range for electric cars

If electric vehicles are to achieve greater distances, it's not only a matter of optimizing their batteries. Instead, the entire power train has to be improved. A Fraunhofer team is therefore developing electronic control ...

Energy & Green Tech

Thermoelectric technologies can help power a zero-carbon future

Thermometers are an under-appreciated marvel of human ingenuity built upon an understanding of relatively simple physical principles. Mercury and alcohol thermometers rely on the volume of liquids growing or shrinking in ...

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Copper

Copper (pronounced /ˈkɒpər/) is a chemical element with the symbol Cu (Latin: cuprum) and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is rather soft and malleable and a freshly-exposed surface has a pinkish or peachy color. It is used as a thermal conductor, an electrical conductor, a building material, and a constituent of various metal alloys.

Copper metal and alloys have been used for thousands of years. In the Roman era, copper was principally mined on Cyprus, hence the origin of the name of the metal as Cyprium, "metal of Cyprus", later shortened to Cuprum. There may be insufficient reserves to sustain current high rates of copper consumption. Some countries, such as Chile and the United States, still have sizable reserves of the metal which are extracted through large open pit mines.

Copper compounds are known in several oxidation states, usually 2+, where they often impart blue or green colors to natural minerals such as turquoise and have been used historically widely as pigments. Copper as both metal and pigmented salt, has a significant presence in decorative art. Copper 2+ ions are soluble in water, where they function at low concentration as bacteriostatic substances and fungicides. For this reason, copper metal can be used as an anti-germ surface that can add to the anti-bacterial and antimicrobial features of buildings such as hospitals. In sufficient amounts, copper salts can be poisonous to higher organisms as well. However, despite universal toxicity at high concentrations, the 2+ copper ion at lower concentrations is an essential trace nutrient to all higher plant and animal life. In animals, including humans, it is found widely in tissues, with concentration in liver, muscle, and bone. It functions as a co-factor in various enzymes and in copper-based pigments.

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