Aluminium

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Review Aluminium Content 1. Introduction 2. Characteristics 3. Isotopes 4. Natural occurrence 5. Production and refinement 6. Recycling 7. Chemistry 7.1 Oxidation state +1 7.2 Oxidation state +2 7.3 Oxidation state +3 7.4 Analysis 8. Applications 8.1 General use 8.2 Aluminium compounds 8.3 Aluminium alloys in structural applications 8.4 Household wiring 9. History 10. Etymology 10.1 Nomenclature history 10.2 Present-day spelling 11. Health concerns 12. Effect on plants 13. Conclusion 14. References 1. Introduction Aluminium is a silvery white and ductile member of the boron group of chemical elements. It has the symbol Al; its atomic number is 13. It is not soluble in water under normal circumstances. Aluminium is the most abundant metal in the Earth's crust, and the third

most abundant element therein, after oxygen and silicon. It makes up about 8% by weight of the Earth’s solid surface. Aluminium is too reactive chemically to occur in nature as a free metal. Instead, it is found combined in over 270 different minerals.[4] The chief source of aluminium is bauxite ore. Aluminium is remarkable for its ability to resist corrosion due to the phenomenon of passivation and for the metal's low density. Structural components made from aluminium and its alloys are vital to the aerospace industry and very important in other areas of transportation and building. Its reactive nature makes it useful as a catalyst or additive in chemical mixtures, including being used in ammonium nitrate explosives to enhance blast power. General properties Name, symbol,

number aluminium, Al, 13 Element category other metal Group, period, block 13, 3, p Standard atomic weight 26.9815386(13) g·mol−1 Electron configuration [Ne] 3s2 3p1 Electrons per shell 2, 8, 3 (Image) Physical properties Phase solid Density (near r.t.) 2.70 g·cm−3 Liquid density at m.p. 2.375 g·cm−3 Melting point 933.47 K, 660.32 °C, 1220.58 °F Boiling point 2792 K, 2519 °C, 4566 °F Heat of fusion 10.71 kJ·mol−1 Heat of vaporization 294.0 kJ·mol−1 Specific heat capacity (25 °C) 24.200 J·mol−1·K−1 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 states 3, 2[1], 1[2] (amphoteric oxide) Electronegativity 1.61 (Pauling scale) Ionization energies (more) 1st: 577.5 kJ·mol−1 2nd: 1816.7

kJ·mol−1 3rd: 2744.8 kJ·mol−1 Atomic radius 143 pm Covalent radius 121±4 pm Van der Waals radius 184 pm Miscellanea Crystal structure face-centered cubic Magnetic ordering paramagnetic[3] Electrical resistivity (20 °C) 28.2 nΩ·m Thermal conductivity (300 K) 237 W·m−1·K−1 Thermal expansion (25 °C) 23.1 µm·m−1·K−1 Speed of sound (thin rod) (r.t.) (rolled) 5,000 m·s−1 Young's modulus 70 GPa Shear modulus 26 GPa Bulk modulus 76 GPa Poisson ratio 0.35 Mohs hardness 2.75 Vickers hardness 167 MPa Brinell hardness 245 MPa CAS registry number 7429-90-5 2. Characteristics Aluminium is a soft, durable, lightweight, malleable metal with appearance ranging from silvery to dull grey, depending on the surface roughness. Aluminium is nonmagnetic and nonsparking. It is

also insoluble in alcohol, though it can be soluble in water in certain forms. The yield strength of pure aluminium is 7–11 MPa, while aluminium alloys have yield strengths ranging from 200 MPa to 600 MPa.[5] Aluminium has about one-third the density and stiffness of steel. It is ductile, and easily machined, cast, drawn and extruded. Corrosion resistance can be excellent due to a thin surface layer of aluminium oxide that forms when the metal is exposed to air, effectively preventing further oxidation. The strongest aluminium alloys are less corrosion resistant due to galvanic reactions with alloyed copper.[5] This corrosion resistance is also often greatly reduced when many aqueous salts are present however, particularly in the presence of dissimilar metals. Aluminium atoms