|CLASSIFICATIONS AND CHARACTERISTICS OF METALS|
|Written by Administrator|
|Monday, 28 February 2011 06:50|
Metals are natural elemental, chemical or mineral substances, each possessing a distinctive atomic structure. As compared to non-metal elements, metals are heavy, opaque and except for mercury, solid at ordinary temperatures.
When metals are mined from natural deposits, they sometimes are found in a native or pure state. More commonly, they occur as ores, which are crude, natural compound minerals containing several components, including one or more metals; the rest is non-metallic mineral waste matter. It is possible to separate these components through the controlled application of high heat. At certain temperatures, the metal will melt into a liquid state and separate from the other components.
Various pieces & Types of metals
This process can be refined and repeated to bring a specific metal down to its pure state. Pure metals posses specific physical constants which make their behavior, under certain conditions, predictable. Their properties include their atomic weight, specific gravity and melting point.
Most metals are ductile, malleable and plastic. Plastic, not referring to the common synthetic polymer based products, means the metals can be worked without rupture. The term malleable refers to a metal’s ability to accept deformation by hammering, rolling and extrusion. Ductile refers to a metal’s ability to be elongated without fracture, as in wire drawing. While most metals carry these characteristics, the degree of these qualities differ from metal to metal.
Metals are generally divided into two main categories. These are ferrous and non ferrous metals. Non ferrous includes the noble or precious metals and base metals. Ferrous metals refer to any metal containing iron.