Aluminium
From Simple English Wikipedia, the free encyclopedia
Aluminium (or aluminum) is a chemical element. The symbol for aluminium is Al, and its atomic number is 13. Aluminium is the most abundant metal.
Aluminium is a very good conductor of electricity and heat. It is light and strong. It can be hammered into sheets (malleable) or pulled out into wires (ductile). It is corrosion resistant.
Aluminium has many uses. Much of it is used in overhead power cables. It is also widely used in window frames and aircraft bodies. It is found at home as saucepans, soft drink cans, and cooking foil. Aluminium is also used to coat car headlamps and compact discs.
Aluminium was once considered a precious metal that was even more valuable than gold. This is no longer true because, as technology improved, it became cheaper and easier to make pure aluminium.
Pure aluminium is made from bauxite, a kind of rock that has aluminium and many impurities. The impurities are removed with chemicals and electricity, to leave behind pure aluminium. The aluminium is then melted and poured into containers for storage until it is ready for use.
Pure aluminium is very soft, so a harder metal is almost always added. The harder metal is usually copper. Copper/aluminium alloys are used for ship building purposes, because the aluminium prevents corrosion, and the copper prevents barnacles.
Aluminium prevents corrosion by forming a small, thin layer of aluminium oxide on its surface. This layer protects the metal by preventing oxygen from reaching it. Corrosion can not occur without oxygen.
