Aluminum

Aluminum

Symbol: Al

Atomic number: 13

Average atomic mass: 26.981

Properties

Phase: Solid

Chemical series: Poor Metals

Aluminium is a soft, lightweight metal with appearance ranging from silvery to dull gray, depending on the surface roughness.

Aluminium is nontoxic for somethings but it can damage nerve cells if used in the wrong way,
nonmagnetic, and nonsparking.

Aluminum is a metal in group 13 of the periodic table. Its atoms consist of a single stable isotopes, 27Al. Known as aluminium in other English-speaking countries, it was named after alum, one of its salts that has been known for thousands of years and was used by the Egyptians, Greeks, and Romans as a mordant—a chemical that helps dyes stick to cloth.

Density: 2600-2800 kg/m3
Melting Point: 660 °C
Elastic Modulus: 70-79 GPa
Poisson's Ratio: 0.33
Tensile Strength: 230-570 MPa
Yield Strength: 215-505 MPa
Percent Elongation: 10-25%

Applications/ Uses

Aluminium would not mormally be made in the laboratory as it is so readily available commercially.
Aluminium is mined in huge scales as bauxite (typically Al2O3.2H2O). Bauxite contains Fe2O3, SiO2, and other impurities. In order to isolate pure aluminium, these impurities must be removed from the bauxite. This is done by the Bayer process. This involves treatment with sodium hydroxide (NaOH) solution, which results in a solution of sodium aluminate and sodium silicate. The iron remains behind as a solid. When CO2 is blown through the resulting solution, the sodium silicate stays in solution while the aluminium is precipitated out as aluminium hydroxide. The hydroxide can be filtered off, washed, and heated to form pure alumina, Al2O3.
The next stage is formation of pure aluminium. This is obtained from the pure Al2O3 by an electrolytic method. Electrolysis is necessary as aluminium is so electropositive. It seems these days that electrolysis of the hot oxide in a carbon lined steel cell acting as the cathode with carbon anodes is most common.
This is mostly used for kitchen utensils, outside building decoration, and in thousands of industrial applications where a strong, light, easily contructed material is needed.

History/ Discoveries

The ancient Greeks and Romans used alum. as an astringent and as a mordant in dyeing. In 1761 de Morveau proposed the name alumine for the base in alum, and Lavoisier, in 1787, thought this to be the oxide of a still undiscovered metal.

In 1807, Davy proposed the name aluminum for the metal, undiscoverd at that time,and later agreed to change it to aluminum. Shortly thereafter, the name aluminum was adopeted to conform with the "ium" ending of most elements, and this spelling is now in use anywhere in the world.

In 1888, the first aluminium companies founded in France, Switzerland and the USA

Aluminium was also the accepted spelling in the U.S until 1925, at which the American Chemical Society officially decided to use the name aluminum thereafter in their publications.

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