Aluminium, or Aluminum in American spelling, is an ancient metal and has a diverse range of uses. It was discovered in 1824 and its light weight, high electrical conductivity and high resistant to corrosion has make it an industrially attractive metal.
History and Discovery
The history of alum dates to Greek historian in 5 th century BCE, and over the centuries it was used for various purposes, including defense fabric, dyeing mordant etc. It was identified as a distinct salt of an element in 1530 by Paracelsus. Aluminium was formally discovered as a new metal by Hans Christian Orsted in 1824 [1]. It was named by Humphry Davy in 1812. The word Aluminium has been derived from Latin word that means bitter salt.
Aluminum
| Periodic Table Classification | Group 13 Period 3 |
|---|---|
| State at 20C | Solid |
| Color | Silvery gray metallic |
| Electron Configuration | [Ne] 3s2 3p1 |
| Electron Number | 13 |
| Proton Number | 13 |
| Electron Shell | 2, 8, 3 |
| Density | 2.7 g.cm-3 at 20°C |
| Atomic number | 13 |
| Atomic Mass | 26.98 g.mol -1 |
| Electronegativity according to Pauling | 1.61 |
Occurrence
Aluminium is an abundant metal and is characterized as the third most abundant element in the Earth’s crust (8% by mass). Aluminium is also quite abundant in space and is ranked 12 th among all elements with an abundance of about 3.15 ppm. Aluminium does not occur in native metallic form. And due to its high reactivity, Aluminium is found in combined form in more than 250 different minerals [2]. It primarily exists in form of ores and the most common ore of Aluminium is bauxite. The largest producers of Aluminium in the world are China, Russia, Bahrain, and South Africa.
Physical Characteristics
Aluminium is a greyish silver metal. It is soft, and extremely malleable and ductile. Aluminium is nonmagnetic. It has very low density (2.7 g/cm -3 ). Aluminium is resistant to corrosion and can withstand environmental exposure for significantly long time periods. It is non-absorptive. And Aluminium is highly conductive of electricity and is relatively cheaper than copper.
Chemical Characteristics
Aluminium is a reactive metal. It is readily oxidized when exposed to air. The most common oxidation state of Aluminium is +3. Aluminium reacts with oxygen and sulfur to form oxides and sulfates, which have various industrial applications. It readily reacts with acids and bases.
Significance and Uses
- Aluminium cans for packaging of food items and soft drinks have been widely used since 1958. Aluminium foils are widely used all over the world.
Aluminium alloys are widely used in aerospace industry, for making space shuttles, satellites etc. - Aluminium is used in the manufacturing of cars, trucks, bicycles and marine vessels.
- Aluminium is widely used construction and building material, such as doors, building wire, windows and roofing.
- Aluminium is widely used in making of cooking utensils, furniture as well as house hold wiring.
- Aluminium is widely used in making motors, capacitors, generators and transformers.
- It is used as a catalyst in various industrial processes, for example, in formation of sulfur from hydrogen sulfide.
- Aluminium is used as a common drying agent.
- Aluminium phosphate is used in manufacturing of various cosmetic products, dental cement and paints.
- Aluminium is used as an immune booster in various vaccine [3].
Health Hazards
Aluminium is not toxic. In most cases, it is well tolerated if ingested or inhaled by humans or plants. However, very rare evidence of Aluminium toxicity is related to vitamin D deficiency, anemia and renal damage. Inhalation of powdered welding fumes of Aluminium can lead to fibrosis of the lungs [4]. In environment, Aluminium can affect the soil fertility as it reacts with phosphate and makes it less available for the plants [5].
Isotopes of Aluminium
Aluminium has only one stable isotope, Aluminium-27. Among the radioactive isotopes, the most stable is Aluminium-26 and have a half life of about 720,000 years.
REFERENCES
[1]. Royal Danish Academy of Sciences and Letters (1827). Det Kongelige Danske Videnskabernes Selskabs philosophiske og historiske afhandlinger [The philosophical and historical dissertations of the Royal Danish Science Society] (in Danish). Popp. pp. XXV–XXVI.
[2]. Shakhashiri, B. Z. (17 March 2008). “Chemical of the Week: Aluminium” (PDF). SciFun.org. University of Wisconsin. Archived from the original (PDF) on 9 May 2012. Retrieved 4 March 2012.
[3]. Singh, Manmohan (3 August 2007). Vaccine Adjuvants and Delivery Systems. John Wiley & Sons. pp. 81–109. ISBN 978–0-470-13492-4.
[4]. al-Masalkhi, A.; Walton, S. P. (1994). “Pulmonary fibrosis and occupational exposure to Aluminium”. The Journal of the Kentucky Medical Association. 92 (2): 59–61. ISSN 0023-0294. PMID 8163901
[5]. https://www.lenntech.com/periodic/elements/al.htm