Aluminum (symbol Al, atomic number 13) is a light yet extremely strong chemical element that makes up about 8% of the Earth's crust by mass. Mainly used in industry, it is also a key element in many technological and construction applications.
Contribution of Aluminum to Modern Materials
Aluminum is a valuable material in many sectors, particularly in aerospace, automotive, electronics, and construction materials manufacturing, due to its lightness and corrosion resistance. Its ability to be recycled without loss of quality is also a major asset for modern industries.
History of Discovery
1825: First isolation by Hans Christian Ørsted Danish chemist Hans Christian Ørsted was the first to isolate small amounts of pure aluminum in 1825 by reducing aluminum chloride with potassium.
1854: First industrial production by Henri Etienne Sainte-Claire Deville Henri Etienne Sainte-Claire Deville developed a more efficient process for obtaining pure aluminum on a large scale, a major technological advancement at the time.
Atomic Structure
Constitution: The aluminum atom has 13 protons, 14 neutrons, and 13 electrons, with an electron configuration of 1s² 2s² 2p⁶ 3s² 3p¹. Isotopes:
Aluminum-27 (²⁷Al): stable isotope, representing virtually all natural aluminum.
Physical Properties
Light, ductile, and malleable metal.
Molar mass: 26.98 g/mol
Melting point: 933.47 K (660.32 °C)
Boiling point: 2792 K (2519 °C)
Density: 2.70 g/cm³
Excellent thermal and electrical conductivity.
Corrosion-resistant due to the formation of a protective oxide layer.
Chemical Reactivity
Reacts with oxygen to form a layer of aluminum oxide (Al₂O₃), making it corrosion-resistant.
Reacts with strong acids and bases to form aluminum salts.
Can be used in reduction reactions, such as the thermite reaction (reduction of iron oxide).
Industrial and Technological Applications
Manufacture of light and strong parts for aerospace, automotive, and transportation structures.
Used in food packaging, beverage cans, and construction materials due to its lightness and corrosion resistance.
Key role in the electrical and electronics industry, where it is used in cables, capacitors, and other components.
Recycling of aluminum to produce new objects without loss of quality.
Biological and Ecological Role
Aluminum is not essential for living organisms and can be toxic at high concentrations, affecting plant growth and human health.
In soils, excess aluminum can be released by pollution and affect the health of aquatic ecosystems.
Environmental and Industrial Challenges
Pollution issues related to aluminum extraction (Bayer process), which requires large amounts of energy and generates toxic waste.
Recycling challenge: although aluminum can be recycled indefinitely without loss of quality, a large portion of produced aluminum is still discarded after a single use.
