Copper is a transition metal located in the 11th column of the periodic table. Denoted by the symbol Cu, copper was the first metal used by the humankind. It is not very reactive and is found in the crust of the earth in its pure form. That is why ancient civilizations benefited from it. Copper has an atomic number of 29 and it’s melting and boiling points are 1084° and 2562°C, respectively. It also has biological significance as a trace of dietary mineral.
Copper is a very ductile metal and has a light orange color. While it is not very reactive, it does react to air and water if exposed for prolonged periods. If exposed to air, copper tarnishes and becomes dark brown in color and upon exposure to water, copper corrodes and forms a green carbonate called Verdigris. It is also a good thermal conductor and is fairly resistant to corrosion. Copper is also an excellent conductor of electricity and is primarily used for electrical wiring and cable.
It ductile nature also makes it easy to bend it and stretch it for use as electric wire and cable. Other members of copper’s group are gold, silver and roentgenium. All members of this group are ductile in nature and are good conductors of electricity. Chile in particular and Andes region in South America in general are the largest producers of mined copper in the world. Chile alone accounts for 33 percent of total copper production.
About 60 percent of copper is used for manufacturing electrical wire and cable. Copper wire is used in power generation, transmission, distribution, telecommunication and other electrical circuits. Other major applications of copper are in roofing/plumbing and manufacture of industrial machinery. However, copper alloys like brass and bronze are commonly used when a harder material is required for industrial use.
Listed below are some very interesting and rarely known facts about copper:
- Copper got its name from the word ‘Cuprum’, which is the Latin name of Cyprus, the largest site of copper mining during the time of Roman Empire. The symbol Cu is also derived from there.
- Until 1982, US penny was made from 95% copper and 5% zinc. However, now the composition is 97.5% zinc and 2.5% copper. The reason for the reversal is that the copper was worth more than the penny with the original composition.
- The best known copper structure in the world is the famed Statue of Liberty in New York City, United States. The greenish color of the statue is due to the formation of copper carbonate, verdigris as a result of copper’s reaction with air and moisture.
- Copper is found in the human liver, muscle and bones. Human body contains 1.4 to 2.1 mg of copper per kilogram of body mass.
- Copper has a high electrical conductivity. In fact, silver is the only element which has an electrical conductivity, higher than copper.
- Most of the copper today is extracted from minerals like copper carbonates and copper sulfides.
- Copper is 100% recyclable, which is good news considering the ever increasing demand of copper. About 40% of world’s copper need is met by recycled copper.
- Copper age started with the discovery of copper in 9000BC and ended with the start of Bronze Age between 3700-3000 BC.
- The largest single piece of copper ever found, weighed more than 520 tons.
- Most of the metals are silver or grey in color. Copper is one of very few that is not. Others being gold, cesium and osmium which is blue in color.
- ‘Chuqui’ in Chile is the largest open-pit copper mine in the world. With a depth of 850 meters, it the second deepest open-pit copper mines in the world.