Aluminum (Al)

Stable Isotopes of Aluminum

Isotope Z(p) N(n) Atomic Mass Natural Abundance Nuclear Spin
Al-27 13 14 26.9815384 100.00% 5/2+



Hans Christian Oersted first isolated aluminum (also known as "aluminium") in Denmark in 1825. Its name originates with the Latin word alumen, meaning "alum." Aluminum is the third most abundant element in the earth's crust, accounting for 8.13% by weight. It is is a silvery-white malleable metal with a cubic crystal structure; it is insoluble in water and soluble in acids and alkalis.

Ancient Greeks and Romans used alum in medicine (as an astringent) and in the dyeing process. Today, aluminum alloys have numerous applications. They are used extensively in electrical transmission lines, coated mirrors, utensils, packages, toys, and in the construction of aircrafts and rockets.

On the other hand, finely divided aluminum dust is moderately flammable and explodes by heat or contact with strong oxidizing chemicals. Chronic inhalation of the powder can cause aluminosis, a type of pulmonary fibrosis. It is almost nontoxic by ingestion.

Properties of Aluminum

Name Aluminum
Symbol Al
Atomic number 13
Atomic weight 26.98154
Standard state Solid at 298 °K
CAS Registry ID 7429-90-5 
Group in periodic table 13 
Group name None 
Period in periodic table
Block in periodic table p-block 
Color Silvery
Classification Metallic 
Melting point 660.37 °C
Boiling point 2467 °C
Thermal conductivity 235 W/(m·K)
Electrical resistivity 2.6548 μΩ·cm at 0 °C
Electronegativity 1.50  
Specific heat 940 J/(kg·K)
Heat of vaporization 294 kJ·mol-1
Heat of fusion 10.7 kJ·mol-1
Density of solid 2.70 g/cm3 
Electron configuration [Ne]3s23p1
Oxidation state  +3

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