Man has a long history with the reddish metallic element copper (Cu). The name of the element derives from the Latin word “cuprum” meaning “from the island Cyprus”. Cyprus supplied many of the ancient European civilizations with their supply of the metal.
Copper with an atomic mass of 63.546 and a density of 63.546 has two oxidation states +1 and +2 and an ionization energy of 7.726 eV. Its meting point is 1084.62°C (1984.32°F, 1357.77 K) and boils at 2562°C (4644°F, 2835 K). With an atomic number of 29, this transition metal occurs in period 4 and group 11 of the periodic table.
Ancient man prized the metal for its decorative value and some copper beads found in Iraq are possibly 11,000 years old. Pure copper is a soft metal and unsuitable for the making of tools or weapons. When man learned to form alloys of copper, his relationship with the metal changed. Humans found that alloyed with about 25% tin copper forms the harder metal bronze. About 5,000 years ago the Bronze Age saw the start of man’s use of metallic tools and weapons.
Today copper alloys are still of use. Brass, gunmetal and Monel 400 are all alloys of copper. The Romans started using brass, a copper alloy containing 5-45% zinc, about 2,500 years ago. Monel 400, a corrosion resistant alloy of copper and nickel, is of use in a number of industries such as marine engineering. Gunmetal is an alloy of copper, tin, lead and zinc used for casting for about 2000 years got its name from its use in the production of early canons. While no longer used in munitions gunmetal is of use in the casting of statues as well as gas tight pipe-fittings.
While some copper is available as native copper most of the supply comes from its mineral ores such as cuprite, tenorite, malachite, chalcocite, covellite and bornite. Economic deposits of these ores occur in many countries primarily United States, Chile, Zambia, Zaire, Peru and Canada. Naturally occurring copper consists of two isotopes copper-63 (69.17%) and copper-65 (30.83%).
Copper is a very good conductor of electricity second only to silver. As it is far cheaper than silver, the electrical industry uses large quantities of the metal particularly in the form of wire.
It is not only in its metallic form that copper has its uses. Copper sulphate also known as blue vitriol has a use as an algaecide in the water industry as well as a poison in agriculture. In addition, copper sulphate acts as pigment in some inks. Other important compounds of copper include cupric chloride (fixes dyes to fabrics), cuprous chloride (poisonous compound used to absorb carbon dioxide) and copper cyanide (used in electroplating).
Biologically copper is an essential element in very small quantities. However, in larger quantities it is toxic. The antimicrobial activity of copper as seen in copper sulfates algaecidal properties has the potential in the environmental control of some pathogenic bacteria.
Copper, one of the Earth’s better-known metallic elements has had a long history with humans and looks to have a continuing future.
Jefferson Lab Science Education
Los Alamos National Laboratory’s Chemistry Division
Air Craft Materials UK
Copper Development Association