Aluminium

For other uses, see Aluminium (disambiguation).

Aluminium, 13Al
Aluminium
Pronunciation
Alternative nameAluminum (U.S., Canada)
AppearanceSilvery gray metallic
Standard atomic weight Ar°(Al)
Aluminium in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson
B
↑
Al
↓
Ga
magnesium ← aluminium → silicon
Atomic number (Z)13
Groupgroup 13 (boron group)
Periodperiod 3
Block  p-block
Electron configuration[Ne] 3s2 3p1
Electrons per shell2, 8, 3
Physical properties
Phase at STPsolid
Melting point933.47 K ​(660.32 °C, ​1220.58 °F)
Boiling point2743[4] K ​(2470 °C, ​4478 °F)
Density (at 20 °C)2.699 g/cm3[5]
when liquid (at m.p.)2.375 g/cm3
Heat of fusion10.71 kJ/mol
Heat of vaporization284 kJ/mol
Molar heat capacity24.20 J/(mol·K)
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1482 1632 1817 2054 2364 2790
Atomic properties
Oxidation statescommon: +3
−2,? −1,? 0,[6] +1,[7][8] +2[9]
ElectronegativityPauling scale: 1.61
Ionization energies
  • 1st: 577.5 kJ/mol
  • 2nd: 1816.7 kJ/mol
  • 3rd: 2744.8 kJ/mol
  • (more)
Atomic radiusempirical: 143 pm
Covalent radius121±4 pm
Van der Waals radius184 pm
Color lines in a spectral range
Spectral lines of aluminium
Other properties
Natural occurrenceprimordial
Crystal structure ​face-centered cubic (fcc) (cF4)
Lattice constant
Face-centered cubic crystal structure for aluminium
a = 404.93 pm (at 20 °C)[5]
Thermal expansion22.87×10−6/K (at 20 °C)[5]
Thermal conductivity237 W/(m⋅K)
Electrical resistivity26.5 nΩ⋅m (at 20 °C)
Magnetic orderingparamagnetic[10]
Molar magnetic susceptibility+16.5×10−6 cm3/mol
Young's modulus70 GPa
Shear modulus26 GPa
Bulk modulus76 GPa
Speed of sound thin rod(rolled) 5000 m/s (at r.t.)
Poisson ratio0.35
Mohs hardness2.75
Vickers hardness160–350 MPa
Brinell hardness160–550 MPa
CAS Number7429-90-5
History
Namingfrom alumine, obsolete name for alumina
PredictionAntoine Lavoisier (1782)
DiscoveryHans Christian Ørsted (1824)
Named byHumphry Davy (1812[a])
Isotopes of aluminium
Main isotopes[11] Decay
abun­dance half-life (t1/2) mode pro­duct
26Al trace 7.17×105 y β+84% 26Mg
ε[12]16% 26Mg
γ –
27Al 100% stable
 Category: Aluminium
| references

Aluminium (or aluminum in North American English) is a chemical element; it has symbol Al and atomic number 13. Aluminium has a density lower than that of other common metals, about one-third that of steel. It has a great affinity towards oxygen, forming a protective layer of oxide on the surface when exposed to air. Aluminium visually resembles silver, both in its color and in its great ability to reflect light. It is soft, nonmagnetic, and ductile. It has one stable isotope, 27Al, which is highly abundant, making aluminium the twelfth-most common element in the universe. The radioactivity of 26Al leads to it being used in radiometric dating.

Chemically, aluminium is a post-transition metal in the boron group; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state. The aluminium cation Al3+ is small and highly charged; as such, it has more polarizing power, and bonds formed by aluminium have a more covalent character. The strong affinity of aluminium for oxygen leads to the common occurrence of its oxides in nature. Aluminium is found on Earth primarily in rocks in the crust, where it is the third-most abundant element, after oxygen and silicon, rather than in the mantle, and virtually never as the free metal. It is obtained industrially by mining bauxite, a sedimentary rock rich in aluminium minerals.

The discovery of aluminium was announced in 1825 by Danish physicist Hans Christian Ørsted. The first industrial production of aluminium was initiated by French chemist Henri Étienne Sainte-Claire Deville in 1856. Aluminium became much more available to the public with the Hall–Héroult process developed independently by French engineer Paul Héroult and American engineer Charles Martin Hall in 1886, and the mass production of aluminium led to its extensive use in industry and everyday life. In the First and Second World Wars, aluminium was a crucial strategic resource for aviation. In 1954, aluminium became the most produced non-ferrous metal, surpassing copper. In the 21st century, most aluminium was consumed in transportation, engineering, construction, and packaging in the United States, Western Europe, and Japan.

Despite its prevalence in the environment, no living organism is known to metabolize aluminium salts, but this aluminium is well tolerated by plants and animals. Because of the abundance of these salts, the potential for a biological role for them is of interest, and studies are ongoing.

  1. ^ "aluminum". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
  2. ^ "Standard Atomic Weights: Aluminium". CIAAW. 2017.
  3. ^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (4 May 2022). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
  4. ^ Zhang, Yiming; Evans, Julian R. G.; Yang, Shoufeng (2011). "Corrected Values for Boiling Points and Enthalpies of Vaporization of Elements in Handbooks". J. Chem. Eng. Data. 56 (2): 328–337. doi:10.1021/je1011086.
  5. ^ a b c Arblaster, John W. (2018). Selected Values of the Crystallographic Properties of Elements. Materials Park, Ohio: ASM International. ISBN 978-1-62708-155-9.
  6. ^ Unstable carbonyl of Al(0) has been detected in reaction of Al2(CH3)6 with carbon monoxide; see Sanchez, Ramiro; Arrington, Caleb; Arrington Jr., C. A. (1 December 1989). "Reaction of trimethylaluminum with carbon monoxide in low-temperature matrixes". American Chemical Society. 111 (25): 9110-9111. doi:10.1021/ja00207a023. OSTI 6973516.
  7. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 28. ISBN 978-0-08-037941-8.
  8. ^ Dohmeier, C.; Loos, D.; Schnöckel, H. (1996). "Aluminum(I) and Gallium(I) Compounds: Syntheses, Structures, and Reactions". Angewandte Chemie International Edition. 35 (2): 129–149. doi:10.1002/anie.199601291.
  9. ^ Tyte, D. C. (1964). "Red (B2Π–A2σ) Band System of Aluminium Monoxide". Nature. 202 (4930): 383. Bibcode:1964Natur.202..383T. doi:10.1038/202383a0. S2CID 4163250.
  10. ^ Lide, D. R. (2000). "Magnetic susceptibility of the elements and inorganic compounds" (PDF). CRC Handbook of Chemistry and Physics (81st ed.). CRC Press. ISBN 0849304814.
  11. ^ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  12. ^ Mougeot, X. (2019). "Towards high-precision calculation of electron capture decays". Applied Radiation and Isotopes. 154 (108884). doi:10.1016/j.apradiso.2019.108884.


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