Here's why:

* Chemical properties describe how a substance reacts with other substances. Diamond's resistance to corrosion is a result of its strong carbon-carbon bonds, making it very stable and unreactive.

* Corrosion is a chemical process where a material deteriorates due to reactions with its environment.

* Diamond's inertness to most chemicals is a direct result of its chemical composition and bonding structure.

Therefore, its resistance to corrosion is a characteristic that arises from its chemical makeup, making it a chemical property.