E N C Y C L O P E D I A

Aluminium

Magnesium - Aluminium - Silicon
B
Al
Ga  
 
 

Full table
General
Name, Symbol, Number Aluminium, Al, 13
Chemical series True metals
Group, Period, Block 13 (IIIA), 3 , p
Density, Hardness 2700 kg/m3, 2.75
Appearance silvery
Atomic Properties
Atomic weight 26.981538 amu
Atomic radius (calc.) 125 (118) pm
Covalent radius 118 pm
van der Waals radius no data
Electron configuration [Ne]33s2 3p1
e- 's per energy level 2, 8, 3
Oxidation states (Oxide) 3 (amphoteric)
Crystal structure Cubic face centered
Physical Properties
State of matter solid
Melting point 933.47 K (1220.58 °F)
Boiling point 2792 K (4566 °F)
Molar volume 10.00 ×1010-3 m3/mol
Heat of vaporization 293.4 kJ/mol
Heat of fusion 10.79 kJ/mol
Vapor pressure 2.42 E-06 Pa at __ K
Speed of sound 5100 m/s at 933 K
Miscellaneous
Electronegativity 1.61 (Pauling scale)
Specific heat capacity 900 J/(kg*K)
Electrical conductivity 37.7 106/m ohm
Thermal conductivity 237 W/(m*K)
1st ionization potential 577.5 kJ/mol
2nd ionization potential 1816.7 kJ/mol
3rd ionization potential 2744.8 kJ/mol
4th ionization potential 11577 kJ/mol
5th ionization potential 14842 kJ/mol
6th ionization potential 18379 kJ/mol
7th ionization potential 23326 kJ/mol
8th ionization potential 27465 kJ/mol
9th ionization potential 31853 kJ/mol
10th ionization potential 38473 kJ/mol
Most Stable Isotopes
iso NA half-life DM DE MeV DP
26Al {syn.} 7.17 E5 y Epsilon 4.004 26Mg
27Al 100% Al is stable with 14 neutrons
SI units & STP are used except where noted.

Aluminium or aluminum (in North American English) is a chemical element in the periodic table with the symbol Al and atomic number 13. A silvery, ductile metal, aluminium is found primarily as the ore bauxite and is remarkable for its resistance to oxidation, its strength, and its light weight. Aluminium is used in many industries to make millions of different products and is very important to the world economy. Structural components made from aluminium are vital to the aerospace industry and very important in other areas of transportation and building in which light weight, durability, and strength are needed.

Table of contents
1 Notable characteristics
2 Applications
3 History
4 Occurrence & resources
5 Isotopes
6 Precautions
7 Spelling
8 External Links

Notable characteristics

Aluminium is a soft, lightweight and but strong metal with a dull silver-gray appearance, due to a thin layer of oxidation that forms quickly when it is exposed to air and which prevents further corrosion. Aluminium weighs about one-third as much as steel or copper; is malleable, ductile, and easily machined and cast; and has excellent corrosion resistance and durability. It is also nonmagnetic and nonsparking and is the second most malleable metal and the sixth most ductile.

Applications

Whether measured in terms of quantity or value, aluminium's use exceeds that of any other metal except iron, and it is important in virtually all segments of the world economy. Pure aluminium is soft and weak, but it can form alloys with small amounts of copper, magnesium, manganese, silicon, and other elements to make alloys having a variety of useful properties.

These alloys form vital components of aircraft and rockets. When aluminium is evaporated in a vacuum it forms a coating that reflects both visible light and radiant heat. These coatings form a thin layer of protective aluminium oxide that does not deteriorate as silver coatings do. Coating telescope mirrors is another use of this metal.

Some of the many uses for aluminium are in

  • Transportation (automobiles, airplanes, trucks, railcars, marine vessels, etc.)
  • Packaging (cans, foil, etc.)
  • Construction (windows, doors, siding, etc.)
  • Consumer durable goods (appliances, cooking utensils, etc.)
  • Electrical transmission lines (because of its light weight, even though its electrical conductivity is only 60% of copper's)
  • Machinery.

Its oxide, alumina, is found naturally as corundum, emery, ruby, and sapphire and is used in glass making. Synthetic ruby and sapphire are used in lasers for the production of coherent light.

Aluminium oxidizes very energetically and as a result has found use in solid rocket fuels and thermite.

History

Friedrich Wöhler is generally credited with isolating aluminium (Latin alumen, alum) in 1827. However, this metal was produced for the first time in impure form two years earlier by Danish physicist and chemist Hans Christian Ørsted. Henri Sainte-Claire Deville presented in a book in 1859 two improvements to the process as to substitute potassium to sodium and double instead of