Elements for Kids
Aluminum
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Characteristics and Properties
In standard conditions aluminum is a fairly soft, strong, and lightweight metal. Its color is silvery-gray. Pure aluminum is a very reactive element and is rarely found on Earth in its free form.
Aluminum acts as an excellent conductor of electricity and heat, but is non-magnetic. When it is exposed to the air, a thin layer of aluminum oxide is formed on the surface of the metal. This prevents further corrosion and rusting.
Other important characteristics of aluminum include low density (which is only around three times that of water), ductility (which allows it to be stretched into a wire), and malleability (which means it can be easily formed into a thin sheet).
Where is aluminum found on Earth?
Aluminum is the third most abundant element and the most abundant metal found in the Earth's crust. It is generally found on Earth in minerals and compounds such as feldspar, beryl, cryolite, and turquoise.
Extracting aluminum from minerals, however, is very expensive. Fortunately, the ore bauxite contains large amounts of aluminum oxide. Modern processes allow for aluminum to be obtained from bauxite fairly cheaply allowing for the metal to be used in a number of applications.
How is aluminum used today?
Because of its abundance, low cost, and useful qualities, aluminum is used in thousands of products. It is often used as a metal because of its light weight.
Most aluminum metal used in industry is an alloy where aluminum is combined with other elements such as copper, zinc, silicon, and magnesium. Applications for aluminum alloys include soda cans, automobile parts, bicycles, aluminum foil, power lines, siding for houses, and even baseball bats.
Other applications for aluminum compounds includes aluminum sulfate (used for water treatment), aluminum oxide (used in various industrial processes), and aluminum chloride (used in refining petroleum).
How was it discovered?
Danish chemist Hans Christian Orsted first produced a metal he thought was aluminum in 1825 and suggested that it was a new element. Credit is also given to Friedrich Wohler for first isolating the element in 1827.
Where did aluminum get its name?
Aluminum gets its name from the mineral alum, which gets its name from the Latin word "alumen" meaning "bitter salt."
Isotopes
There are a number of aluminum isotopes, but only two occur naturally: aluminum-27 (stable) and aluminum-26 (radioactive). The vast majority of aluminum, over 99%, is aluminum-27.
Interesting Facts about Aluminum
- It makes up around 8% of the Earth's crust by weight.
- Aluminum is 100% recyclable and maintains the same physical properties after recycling as the original aluminum.
- When aluminum reacts with hydrochloric acid, it produces hydrogen gas.
- Recycling aluminum takes only around 5% of the energy it takes to extract aluminum from the ore bauxite.
- It has no known function in biology.
- An alternative spelling often used for the element is "aluminium".
- In the mid-1800s aluminum was more expensive than gold.
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