Aluminium is a silvery-white, soft, nonmagnetic, ductile metal. Aluminium is the third most abundant element in the Earth's crust (after oxygen and silicon) and its most abundant metal. Aluminium makes up about 8% of the crust by mass, though it is less common in the mantle below. Aluminium metal is so chemically reactive that native specimens are rare and limited to extreme reducing environments. Instead, it is found combined in over 270 different minerals. The chief ore of aluminium is bauxite.
Aluminium is remarkable for the metal's low density and its ability to resist corrosion through the phenomenon of passivation. Aluminium and its alloys are vital to the aerospace industry and important in transportation and structures, such as building facades and window frames. The oxides and sulfates are the most useful compounds of aluminium.
| Name | Aluminium | Group number | 13 |
| Symbol | Al | Group name | (None) |
| Atomic Number | 13 | Period number | 3 |
| Atomic Weight | 26.981538 (2) | Block | p-block |
| CAS Registry ID | 7429-90-5 | Density (g/cm 3) | 2.702 |
- • Melting point – 660ºC
- • Boiling point – 2, 520ºC
- • Resistivity – 2.67 micro ohm-cm at 20ºC
- • Standard state: solid at 298 K
- • Colour: Silvery
- • Classification: Metallic
Pure Aluminium is soft and lacks strength, but alloys with small amounts of copper, magnesium, silicon, manganese, and other elements have very useful properties. Aluminium is an abundant element in the earth's crust, but it is not found free in nature. The Bayer process is used to refine aluminium from bauxite, an aluminium ore.
