How does aluminum oxide form?

Aluminum oxide forms through a process known as oxidation, where aluminum reacts with oxygen in the air. This reaction is typically exothermic and can occur at room temperature, especially in the presence of moisture. When aluminum is exposed to oxygen, it forms a thin, protective layer of aluminum oxide on its surface. This layer prevents further oxidation and is what gives aluminum its corrosion resistance. In industrial settings, aluminum oxide can also be produced through electrolysis of aluminum oxide dissolved in molten cryolite.