Aluminum
Al
Description
Aluminum (Al) is a silvery-white, lightweight metal belonging to the post-transition metal group. It is the most abundant metallic element in the Earth's crust and the third most abundant element overall, after oxygen and silicon.
In its pure form, aluminum is highly reactive, meaning it is rarely found in nature as a free element. Instead, it is usually found in minerals like bauxite.
Crystallographic Structure
For those analyzing material physics or building 3D visualizations, aluminum is a textbook example of high-symmetry packing. It crystallizes in the Face-Centered Cubic (FCC) lattice system.
- Lattice Parameter: $a = 4.049$ Å at room temperature.
- Coordination Number: 12 (each atom is in contact with 12 neighbors).
- Packing Factor: 0.74 (the most efficient packing possible for spheres).
- Symmetry: Highly ductile and easily workable due to the multiple slip planes available in the FCC structure.
Properties
Atomic & Physical Properties
Aluminum is prized for its low density—roughly one-third that of steel—and its remarkable ability to resist corrosion through the formation of a thin, protective oxide layer.
- Atomic Number: 13
- Atomic Mass: 26.98 u
- Melting Point: 660.3°C
- Boiling Point: 2,470°C
- Density: 2.70 g/cm³
Applications
- Aerospace & Transport: Used in aircraft skins, frames, and automotive engine blocks where weight reduction is critical.
- Construction: Modern skyscrapers utilize aluminum for window frames and curtain walls due to its strength-to-weight ratio.
- Packaging: Widely used in cans, foils, and pharmaceutical packaging because it is non-toxic and impermeable to light and air.
Unit Cell Axes
a=4.05 b=4.05 c=4.05
Unit Cell Angles
α=90° β=90° γ=90°
Lattice Type
fcc
Grid Expansion
Appearance
Coordination