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Copper. face-centered cubic (fcc) (cF4) Copper is a chemical element; it has symbol Cu (from Latin cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity ...
Usage. On metal, patina is a coating of various chemical compounds such as oxides, carbonates, sulfides, or sulfates formed on the surface during exposure to atmospheric elements (oxygen, rain, acid rain, carbon dioxide, sulfur -bearing compounds). [2] In common parlance, weathering rust on steel is often mistakenly [3] referred to as patina.
Malachite is a copper carbonate hydroxide mineral, with the formula Cu 2 CO 3 (OH) 2.This opaque, green-banded mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal, fibrous, or stalagmitic masses, in fractures and deep, underground spaces, where the water table and hydrothermal fluids provide the means for chemical precipitation.
Rust is a commonly used metaphor for slow decay due to neglect, since it gradually converts robust iron and steel metal into a soft crumbling powder. A wide section of the industrialized American Midwest and American Northeast , once dominated by steel foundries , the automotive industry , and other manufacturers, has experienced harsh economic ...
The long life of copper when exposed to natural waters is a result of its thermodynamic stability, its high resistance to reacting with the environment, and the formation of insoluble corrosion products that insulate the metal from the environment. The corrosion rate of copper in most drinkable waters is less than 2.5 μm/year, at this rate a ...
Azurite has the formula Cu 3 (CO 3) 2 (OH) 2, with the copper(II) cations linked to two different anions, carbonate and hydroxide. It is one of two relatively common basic copper(II) carbonate minerals, the other being bright green malachite. Aurichalcite is a rare basic carbonate of copper and zinc. [8]
Pitting corrosion. Severe pitting corrosion problems caused by chloride ions on a truss beam of the Nandu River Iron Bridge (Hainan Province, China) leading to the complete rupture of a metallic element. Pitting corrosion, or pitting, is a form of extremely localized corrosion that leads to the random creation of small holes in metal.
Galvanic corrosion. Corrosion of an iron nail wrapped in bright copper wire, showing cathodic protection of copper; a ferroxyl indicator solution shows colored chemical indications of two types of ions diffusing through a moist agar medium. Galvanic corrosion (also called bimetallic corrosion or dissimilar metal corrosion) is an electrochemical ...