Aluminium

**Physical Characteristics of Aluminium:**
– Aluminium is a chemical element with symbol Al and atomic number 13.
– It has a density lower than that of other common metals, about one-third that of steel.
– Aluminium forms a protective layer of oxide on the surface when exposed to air.
– It visually resembles silver and has a great ability to reflect light.
– Aluminium is soft, nonmagnetic, and ductile.
– Aluminium metal appears silvery white to dull gray.
– Aluminium mirrors are highly reflective in the ultraviolet and infrared spectrum.
– Anodizing aluminium adds a protective oxide layer to prevent wear.
– The density of aluminium is 2.70g/cm^3, about one-third that of steel.

**Isotopes and Electron Shell of Aluminium:**
– Only Al-27 is stable among aluminium isotopes.
– Al-27 is the only primordial aluminium isotope on Earth.
– Aluminium has an electron configuration of Ne 3s^2 3p^1.
– A free aluminium atom has a radius of 143pm.
– Aluminium atoms form a face-centered cubic crystal system at standard temperature and pressure.
– Aluminium can surrender its three outermost electrons in chemical reactions.
– The electronegativity of aluminium is 1.61 (Pauling scale).

**Properties of Aluminium – Mechanical, Thermal, Electrical, and Chemical:**
– Pure aluminium yield strength: 7-11 MPa, while aluminium alloys have yield strengths of 200-600 MPa.
– Aluminium is ductile with 50-70% percent elongation and malleable, easily drawn and extruded.
– It is an excellent thermal and electrical conductor, around 60% conductivity of copper.
– Aluminium is essentially unaffected by static magnetic fields.
– Combines characteristics of pre- and post-transition metals.
– High chemical affinity to oxygen and resists corrosion due to passivation.
– Reacts with nonmetals upon heating.

**Compounds and Derivatives of Aluminium:**
– Majority of compounds feature aluminium in oxidation state 3+.
– Almost all aluminium(III) compounds are colorless.
– Aluminium hydrolysis forms a precipitate of aluminium hydroxide.
– Aluminium trichloride has major industrial uses.
– Compounds like AlR3 and AlR1.5 exist in organoaluminium compounds.
– Aluminium trialkyls and triaryls are reactive and volatile.
– Aluminium alloys well with most metals except alkali and group 13 metals.

**History, Production, and Usage of Aluminium:**
– First record of alum dates back to 5th century BCE by Greek historian Herodotus.
– Industrial production of aluminium was established in 1856 by Henri Etienne Sainte-Claire Deville.
– World production of aluminium exceeded 100,000 metric tons in 1916.
– Aluminium surpassed copper in production in 1954, becoming the most produced non-ferrous metal.
– China is the top producer of aluminium with a world share of 55%.
– Recycling has become an important task in the aluminium industry, reducing energy consumption and waste.