Copper is a metal that occurs naturally throughout the environment, in rocks, soil, water, and air. Copper is an essential element in plants and animals (including humans), which means it is necessary for us to live. Therefore, plants and animals must absorb some copper from eating, drinking, and breathing.
The use of copper dates back to prehistoric times. The metal, its compounds, and alloys have numerous applications in every sphere of life–making it one of the most important metals. Practically all coinages in the world are made out of copper or its alloys. Its alloys, bronze and brass, date from ancient times. More modern alloys such as monel, gun metals, and berylliumcopper also have wide applications. The metal is an excellent conductor of electricity and heat and is used in electric wiring, switches and electrodes. Other applications are in plumbing, piping, roofing, cooking utensils, construction materials, and electroplated protective coatings. Its compounds, namely the oxides, sulfates, and chlorides, have numerous of commercial applications.
Copper is distributed widely in nature as sulfides, oxides, arsenides, arsenosulfides, and carbonates. It occurs in the minerals cuprite, chalcopyrite, azurite, chalcocite, malachite and bornite. Most copper minerals are sulfides or oxides. Native copper contains the metal in uncombined form.
Copper combines violently with chlorine trifluoride in the presence of carbon [Mellor 2, Supp. 1, 1956]. Is oxidized by sodium peroxide with incandescence [Mellor 2:490-93, 1946-1947]. Forms an unstable acetylide when acetylene is passed over samples that have been heated enough to form an oxide coating. Reacts more rapidly in powdered or granular form. Subject to explosive reaction then mixed in finely divided form with finely divided bromates chlorates and iodates of barium, calcium, magnesium, potassium, sodium, or zinc; these reactions are initiated by heat, percussion, and occasionally light friction [Mellor 2:310, 1946-1947]. A solution of sodium azide in Copper pipe with lead joints formed Copper azide and lead azide, both of these compounds can detonate [Klotz, 1973].
Air & Water Reactions
Solid pieces are very slowly oxidized by air to give a green basic carbonate. Solid pieces become covered by a black oxide when heated in air. Insoluble in water.
Reddish lustrous malleable odorless metallic solid.
manufacture of bronzes, brass, other copper alloys, electrical conductors, ammunition, copper salts, works of art.
Reddish brown metal; face-centered cubic crystal; density 8.92 g/cm3; Mohs hardness 2.5 to 3.0; Brinnel hardness 43 (annealed); electrical resistivity 1.71 microhm-cm at 25°C; Poisson's ratio 0.33; melts at 1,083°C; vaporizes at 2,567°C; insoluble in water; dissolves in nitric acid and hot sulfuric acid; slightly soluble in hydrochloric acid; also soluble in ammonium hydroxide, ammonium carbonate and potassium cyanide solutions.