Metals and Alloys

Metals are a group of elements known for their strength, durability and ability to conduct heat and electricity. Most metals are solid at room temperature, although mercury is a well-known exception because it is liquid. They usually have a shiny appearance when freshly cut or polished and can often be shaped without breaking, making them useful for manufacturing.

Iron, copper, aluminum and gold are among the best-known metals. They are found naturally in rocks called ores and are extracted through mining and refining. Each metal has its own properties: copper is an excellent electrical conductor, aluminum is both lightweight and resistant to corrosion, while iron is valued for its strength but can rust when exposed to oxygen and moisture.

An alloy is a material made by combining a metal with one or more other elements to improve its properties. Steel, for example, is mainly iron mixed with a small amount of carbon, making it much stronger than pure iron. Bronze is an alloy of copper and tin, while brass is made from copper and zinc. By selecting different combinations, engineers can create materials that are harder, lighter, more resistant to wear or better able to withstand corrosion.

Metals and alloys are used in buildings, vehicles, tools, medical devices, electronic equipment and countless everyday objects. Recycling them is especially important because metals can often be melted down and reused many times, helping to conserve natural resources and reduce the environmental impact of mining.