Corrosion and Alloys

Metals are among the most widely used materials in the modern world, but they are vulnerable to corrosion — a chemical process that weakens and destroys them over time. Understanding corrosion and how to prevent it, as well as how alloys are used to improve metal properties, is essential for AQA GCSE Chemistry: Using Resources.

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What Is Corrosion?

Corrosion is the destruction of a metal by chemical reactions with substances in the environment. It is an oxidation reaction — the metal atoms lose electrons and form metal oxide (or other compounds).

The most familiar example is the rusting of iron, but all metals can corrode.

Term	Definition
Corrosion	The gradual destruction of a material (usually a metal) by chemical reaction with its environment
Rusting	The specific corrosion of iron (or steel) in the presence of water and oxygen, producing hydrated iron(III) oxide
Oxidation	A reaction where a substance gains oxygen or loses electrons

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Rusting of Iron