Metals are composed of one or more metallic elements, such as iron, aluminum, copper, titanium, gold, and nickel, and also often nonmetallic elements such as carbon, nitrogen, and oxygen.
The atomic structure of metals and their alloys are arranged in a very orderly manner and in comparison to ceramics and polymers, are relatively dense.
With regard to mechanical properties, metals are relatively stiff and strong, yet are ductile, and are resistant to fracture, which accounts for their widespread use in structural application.
Metals are extremely good conductors of electricity and heat, and are not transparent to light, a polished metal surface has a very lustrous appearance.
In addition, some metals have desirable magnetic properties.
