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Aluminum
Aluminum, which is sometimes called aluminum, is the typical metal in the third group in the periodic classification of the elements. Aluminum is the most abundant of the metals and the most widely distributed. It is found in field-spars, micas, koalin, clay, bauxite, cryolite, alunite, corundum and certain gems. Compounds of aluminum have been known for many years and they were recognized as being derived from a metal that had not been isolated.
Aluminum has a very low density, 2.7, it is used in construction when a metal is required and weight is an important consideration. It is ductile, malleable, and can be rolled. Its tensile strength is low in comparison with that of iron; it cannot be machined and polished readily and does not yield good castings. These defects can be overcome by alloying it with other metals. Alloys of copper and aluminum which contain from 5 to 10 per cent of the latter are called aluminum bronzes. They have a fine yellow color resembling gold and are used in making imitation jewelry and statuary.
On account of its low electrical resistance, aluminum is used in certain cases in wires and cables as conductors.
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