Aluminium

**Symbol:** Al

**Atomic number:** 13

**International title:** aluminium

**Relative Atomic Weight:** 26,98

**Information:** Aluminium is lightweight, soft, lustrous, silver-metal coloured. It can be rolled into thin foil so-called aluminium foil (protective packaging material). It is an excellent conductor of both heat and electricity. The compound only exists in the form of an aluminium cation Al³⁺. Aluminium has a great affinity with oxygen.

**Use:** Thanks to its low weight and corrosion resistance (covered by a continuous layer of oxide that protects it) it is used to produce alloys, coins, aluminium profiles in the building industry. It is also used as an electric conductor but usually replaced by copper conductors. It is used in the thermit process, which uses its considerable affinity to oxygen. Aluminium is then able to reduce some metals from the respective oxides.

**Occurrence:** In nature, it is relatively well-represented. It occurs in the form of compounds. Its major rocks include bauxite Al₂O₃·2H₂O; among the minerals comes then cryolite Na₃AlF₆ or the alloy corundum Al₂O₃ (red ruby, blue sapphire).

**Structure:** Aluminium crystallizes into a cubic (cubic) system (a flat-centered base cell).