What word describes physical damage caused by a chemical?

The term that best describes physical damage caused by a chemical is "corrosion." Corrosion refers specifically to the gradual destruction or deterioration of materials, particularly metals, due to chemical reactions with their environment, often involving moisture or other agents. This process results in the weakening and eventual failure of the material, highlighting the tangible effects that chemicals can exert on substances.

The other options, while related to the effects of chemicals, do not encapsulate the concept of physical damage in the same way. Contamination generally refers to the presence of harmful substances in an environment or product, which may not necessarily imply physical damage. Penetration indicates the act of a substance moving into another, often without a destructive implication. Degradation describes a decline in quality or functionality of a material but does not exclusively reflect physical damage caused by chemical reactions.