O aluminum is a chemical element with atomic number 13 and is part of group 13 (family IIIa) of the Periodic Table. It is the most abundant metal in the earth's crust and the third most common element in the world, after oxygen and silicon.
Its main characteristics are: light metal, soft, easy to mold, silvery white in color, electrically conductive and resistant to corrosion.
Another important feature is that aluminum is easily recyclable, so the metal recycling process is widely used and much cheaper than its extraction.
It is found forming compounds with other elements in ores in nature, that is, it does not occur in a pure form, and represents 8% of the weight of the earth's surface.
A wide variety of everyday objects have aluminum in their composition. The best known applications of this metal are: aluminum foil, beverage cans, pans and antiperspirants. Due to its low density, it is widely used in the aerospace industry for making aircraft fuselage.
aluminum properties
- Symbol: Al
- Atomic number: 13
- Atomic mass: 26.982
- Melting point 660.32°C
- Boiling point 2519°C
- Density: 2.70 g/cm3
- Physical state at 20°C: Solid
- Electronic distribution: [Ne] 3s23p1
- Number of isotopes: 22, with Al-27 being the most stable
Aluminum in its pure state is quite reactive, weak and soft. Therefore, it is marketed with the addition of small amounts of other more resistant elements, such as iron and silicon.
Aluminum has an amphoteric character, that is, depending on the medium, it acts as an acid or a base. For example, putting aluminum oxide in contact with potassium hydroxide (KOH), a strong base, or together with hydrochloric acid (HCl), a strong acid, a neutralization reaction will occur, which results in the formation of salt and Water.
Al2O3(s) + 6 HCl (aq) → 2 AlCl3(aq) + 3H2the(l)
Al2O3(s) + 2KOH(aq) → 2 KAlO2(aq) + H2the(l)
Concentrated acids and bases are able to attack materials with aluminum and dissolve them quickly.
aluminum characteristics
Aluminum is a light metal, about three times lighter than iron, easy to process and mold. It is also an excellent conductor of electricity and heat.
It is a durable and corrosion resistant material, because as aluminum reacts easily with oxygen, in contact with air, a layer of aluminum oxide forms under the metal, which acts as a film protective.
Its high reactivity is one of the reasons why pure aluminum is not found in nature. Due to its low toxicity, compounds of this metal are used in cosmetics and in water treatment, for example.
To improve its properties, other elements such as copper, zinc and silicon are joined to aluminum to form metal alloys.
Where is aluminum found?
Feldspar-type rocks, which constitute 60% of the earth's crust, have aluminum in their composition.
The main source of aluminum for commercial exploitation is bauxite ore, whose main constituent is aluminum oxide (Al2O3).
Gemstones such as ruby and sapphire are varieties of the same mineral, corundum, which is an oxide of aluminum (Al2O3) and its color varies according to the existing impurities: the ruby red is due to the presence of chromium and the sapphire blue is due to iron or titanium.
Gain more knowledge with the contents:
- Chemical elements
- metal alloys
- What are metals, examples and properties
Bibliographic references
ATKINS, P.W.; JONES, Loretta. Principles of chemistry: questioning modern life and the environment. 3.ed. Porto Alegre: Bookman, 2006.
FELTRE, Ricardo. Fundamentals of Chemistry: vol. single. 4th ed. Sao Paulo: Moderna, 2005.
Lee, J. D Not so concise inorganic chemistry. Translation of the 5th ed. English. Publisher Edgard Blucher Ltd. 1999.
