Oxidation of metals in the presence of acids or moisture is called:

Corrosion means metals slowly break down because they react with their surroundings. It usually happens when there is moisture or acids, which make oxides, hydroxides, or sulfides on the metal surface. Common examples are the rusting of iron and the tarnishing of silver. Corrosion is a natural change that turns pure metals into more stable forms like oxides or hydroxides.