Metals are opaque, lustrous natural elements that are effective in conducting electricity and heat. The majority of metals used in everyday applications are ductile and malleable and are usually denser than other elemental substances.
Metals such as platinum, gold, copper and silver are found in pure forms, while alloys, such as bronze and brass are made by heating two different kinds of metal together and then allowing the mixture to cool. For example, copper and tin are mixed to create bronze, and copper and zinc are used to make brass. By definition, an alloy is a solid material that is made from the mixing of two or more metals. Metals are naturally hard and can be shiny, rough or dull in appearance.