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1. Any of a large group of chemical elements, including iron, gold, copper, lead, and magnesium, that readily become cations and form ionic bonds, having relatively free valence electrons (electrons in the outer shells). Metals are generally good conductors of electricity because of the freedom of their valence electrons. Metals generally conduct heat well, and in solid form are relatively malleable and ductile compared to other solids. They are usually shiny and opaque. All metals except mercury are solid at room temperature. 2. An alloy, such as steel or bronze, made of two or more metals. 3. In astronomy, any atom except hydrogen and helium. 4. Small stones or gravel, mixed with tar to form tarmac for the surfacing of roads. Usage
Most metallic elements are lustrous or colorful solids that are good conductors of heat and electricity, and readily form ionic bonds with other elements. Many of their properties are due to the fact that their outermost electrons, called valence electrons, are not tightly bound to the nucleus. For instance, most metals form ionic bonds easily because they readily give up valence electrons to other atoms, thereby becoming positive ions (cations). The electrical conductivity of metals also stems from the relative freedom of valence electrons. In a substance composed of metals, the atoms are in a virtual "sea" of valence electrons that readily jump from atom to atom in the presence of an electric potential, creating electric current. With the exception of hydrogen, which behaves like a metal only at very high pressures, the elements that appear in the left-hand column of the Periodic Table are called alkali metals. Alkali metals, such as sodium and potassium, have only one electron in their outermost shell, and are chemically very reactive. (Hydrogen is exceptional in that, although it is highly reactive, its other metallic properties are manifest only at very high pressures.). Our product range includes used rails, copper rods, cathodes and scrap metal (hms 1&2) 80:20.
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