Page 18 - Curriculum Visions Dynamic Book

Ag see Silver
Aluminium (Al)
Element 13.Aluminium is a lightweight, silvery-white metal. It belongs to group 3 (the boron group) in the Periodic Table.
Aluminium is the most common metallic element in the Earth’s crust. It is the third most abundant element on Earth after oxygen and silicon.
It is reactive and is never found as the native metal. It mainly occurs as aluminium oxide.
Aluminium is the most widely used non-ferrous metal. It is non-magnetic and easily worked. However, it was initially so difficult to obtain from its
ore that it was very expensive and so
was regarded as a precious metal. Only when electric power became available and it could be more easily refined did its price drop.At the same time, it found many new uses. By the 1960s aluminium became the most commonly used non- ferrous metal.
It is refined using the Bayer process.
Aluminium is weak and soft in pure form, but is easily alloyed with other metals; then it is transformed into a hard, strong, lightweight material. Copper, magnesium, silicon and manganese are all used as alloying metals.
Key facts...
Name: aluminium
Symbol: Al
Atomic number: 13
Atomic weight: 26.98
Position in Periodic Table: group 3 (13) (boron
group); period 3
State at room temperature: solid
Colour: silvery-white
Density of solid: 2.7 g/cc
Melting point: 660.32°C
Boiling point: 2,519°C
Origin of name: from the Latin word alumen,
meaning alum, a compound of aluminium used in fixing dyes.
The name alumine was first proposed
in 1761 by de Morveau. Davy suggested alumium in 1807 and then agreed to change it to aluminum. Scientists then agreed to change the ending to ‘ium’ to be in line with scientific notation for the newly discovered elements. Aluminium remains the official international scientific spelling. However, in 1925 the American Chemical Society decided to revert to aluminum, which is why there are two spellings for this element.
Shell pattern of electrons: 2–8–3
18
For more on aluminium, see Volume 7: Aluminium in the Elements set.