Aluminium

**Symbol:** Al **Atomic number:** 13 **International name:** Aluminium **Relative Atomic Weight:** 26.98 **Description:** Aluminium, or aluminum, is a lightweight, soft, lustrous metal with a silver color. It can be rolled into thin sheets, known as aluminum foil, which is commonly used as a protective packaging material. Aluminum is an excellent conductor of heat and electricity and typically exists as a trivalent cation Al³⁺ in compounds. It has a strong affinity for oxygen, forming a stable oxide layer that provides corrosion resistance. **Applications:** Because of its low weight and high corrosion resistance, aluminum is widely used to produce various alloys and coins and aluminum profiles for the construction industry. Although used as an electrical conductor, it is often replaced with copper in many applications. Aluminum's strong affinity for oxygen makes it useful in the thermite process, where it reduces other metals from their oxides. **Occurrence:** Aluminum is one of the most abundant elements in the Earth's crust, always found in compound form. Key minerals containing aluminum include bauxite (Al₂O₃·2H₂O), cryolite (Na₃AlF₆) and corundum (Al₂O₃), which occurs as red ruby and blue sapphire. **Structure:** Aluminum crystallizes in a cubic system with a face-centered cubic lattice structure.