Aluminium (or aluminum; see different endings) is a chemical element in the boron group with symbol Al and atomic number 13. It is a silvery-white, soft, nonmagnetic, ductile metal. Aluminium is the third most abundant element (after oxygen and silicon), and the most abundant metal, in the Earth's crust.
Three reasons Aluminum stands out
- 1
A lightweight metal used in everyday packaging.
- 2
It was once considered more precious than gold, and Napoleon served guests with cutlery made from it.
- 3
Recycling it saves a great deal of energy.
The abundant metal that hid in plain sight
Aluminum is common in Earth’s crust but binds oxygen so tightly that extracting the metal requires substantial electricity. Once exposed to air, it forms an ultrathin oxide skin that protects the surface below. That self-protection helps explain its success in aircraft, cans, wiring, and architecture.