Final answer:
Corrosion of metal couplings is an example of chemical damage. When iron is exposed to oxygen and water, it rusts, forming a reddish-orange deposit on the metal surface.
Step-by-step explanation:
Corrosion of metal couplings is an example of chemical damage. Corrosion occurs when metals react with substances in their environment, such as oxygen and water. It results in the degradation and deterioration of metallic materials. For example, when iron is exposed to oxygen and water, it rusts, forming a reddish-orange deposit on the metal surface.