Aluminum Essay Example 5

In the periodic table, 80% of the elements are metals. Of the metals, aluminum is the most abundant in the earth’s crust. Aluminum is concentrated in the outer 10 miles (16 km) of the Earth's crust, of which it constitutes about 8% by weight; it is exceeded in amount only by oxygen and silicon.1 This metal can be found in group 13 (formerly group IIIA) in the periodic table, known as the boron group elements. It is represented by the chemical symbol Al, and has an atomic number of 13. Aluminum, also spelt Aluminium, comes from the word alum, KAl(SO4)2.12H2O, which is potassium aluminum sulfate. This salt was used in Roman times in dyes and medicinal purposes. The metal was called aluminium with the -ium ending being the accepted ending for most elements at that time. This usage persists in most of the world except the United States, where the last i has been dropped from the name.2

In England in the early 1800s, Humphry Davy was able to prepare a number of elements that had been difficult to separate from their compounds -- sodium and potassium in 1807, and magnesium and calcium in 1808. He used electrolysis of molten alkalis for the first two, or powdered oxides mixed with mercury for the others. He tried hard to prepare aluminum metal in this way as well, but failed.3

Aluminum was first prepared in Denmark in 1825 by the Danish physicist and chemist, Hans Christian Oersted when he combined potassium (K) which was dissolved in mercury (Hg) with aluminum chloride (AlCl3). Because his method only prepared an impure form of the metal, credit for its discovery goes to the German scientist, Friedrich Woehler, who in 1827 reacted anhydrous AlCl3 with potassium to isolate aluminum in its pure form. Aluminum is not found free in nature due to its chemically reactive properties. It is found tightly bonded in many compounds. The main source of aluminum though, is the bauxite ore, also called aluminum oxide (Al2O3). Aluminum is generally obtained by