métal

Metal is a material category composed of elements that typically exhibit electrical conductivity, luster, malleability, ductility, and high density. Metals often form crystalline structures and are arranged in metallic bonds. At room temperature most metals are solid, with mercury as a notable exception.

Metals are commonly classified as ferrous or non-ferrous. Ferrous metals contain iron, including steel and cast iron; non-ferrous metals do not contain iron, such as aluminum, copper, and titanium. Further groups include transition metals (like iron, nickel, copper), alkali and alkaline earth metals (lithium, calcium), post-transition metals (tin, lead), and rare-earth elements. Many metals are processed into alloys to enhance properties: steel (iron with carbon and other elements), bronze (copper and tin), brass (copper and zinc).

Occurrence and production: Metals occur in minerals called ores. Extraction typically involves mining, ore concentration, smelting, and refining to obtain pure metal. Energy use and emissions depend on the metal and the process. Recycling metals is widely practiced and helps reduce environmental impact; steel and aluminum have high recycling rates.

Applications: Metals are used in construction, transportation, electronics, machinery, energy storage, and consumer goods. Properties such as strength-to-weight, electrical and thermal conductivity, and resistance to wear make them versatile.

History: The adoption of metal technologies defined major cultural shifts, including the Bronze Age and the Iron Age, and continues to drive modern industry and technology.