IntroductionCopper is Shiny and reddish. Copper is the first metal used by humans and is an important metal in the industry today. Copper is the third most consumed industrial metal in the world. This is only next to iron and aluminium. Mainly copper is being used to make electrical wires, telecommunication cables and electronics. Gold and copper are the only two metals whose colour is not natural silver or grey. Mainly copper occurs in ores. The ores are to be processed for purity before it can be used. But pure copper is being obtained through some chemical reactions also. Human beings are making articles from the metal for at least 8,000 years. People learned how to smelt copper by about 4500 B.C and because of this, there was a further increase in the supplies of copper. The technology for making copper alloys by adding tin to copper was developed and the mixture of these two metals is named as bronze which is harder than copper. This invention is the start of the so-called Bronze Age. In ancient times some countries used copper to make ornaments. In our country also there are some ladies who use the ornaments made out of this metal.
PropertiesThe Atomic number (number of protons in the nucleus) of copper is 29 and its atomic weight is about 63.5. Its symbol is Cu.
Its density is 8.92 grams per cubic centimetre. This is a solid at room temperature
The number of isotopes is about 35 but stable isotopes are only two. These two isotopes are Cu-63 which is 69.15% in naturally available material and the remaining is Cu-65
The metal is ductile and malleable and conducts heat and electricity well. Hence this metal is used in electronics and wiring.
The metal turns green because of an oxidation reaction. The oxidation reaction is nothing but losing electrons. The resulting copper oxide is dull green in colour. This layer formed on the surface of the copper will protect the inside material from getting reacted. This metal will not react with water but react with moist air.
The metals Copper, silver and gold are in the same group of the periodic table. These three metals have one s-orbital electron on top of a filled d-orbit. They are characterized by high ductility and electrical and thermal conductivity. Metallic bonds in copper are not having covalent properties and are weak. The low hardness and high ductility copper are mainly due to this only.
UsesCopper is used for making coins initially by many countries. Pennies were made of pure copper in olden days. In our country also copper coins were in use. Bronze replaced copper for making the coins. But later on the percentage of copper further reduced to 2.5% in bronze from initial 5% keeping the cost factor in view.
Copper is also an essential trace element for the formation of red blood cells.
Copper is available in many foods which are occurring naturally like potatoes, green leafy vegetables, beans and grains. Too much consumption of copper will lead to some health problems.
Copper is having antimicrobial properties and kills viruses and bacteria. In our country, we have a tradition of keeping water in a copper vessel in the bedroom in the nights. There are two uses of this. It stops bacteria spreading in the room and the water will get a little copper dissolved in it that will be good for the body.
Copper is being used very widely in various electronic devices also. In future copper may be found more useful in electronic devices replacing gold and silver. In the creation of "aerogel monolith" studies are going on to use copper nanowires in place of presently used gold and silver wires. An aerogel monolith is a material which is very porous, very light and strong to stand up on its own which almost looks like a dry kitchen sponge.
Closing words Thus this metal will be of many uses for electrical appliances, medicinal applications, electronics and foodstuffs. This metal is going to play a very important role in many varied applications including nanoscience.