Final answer:
Reactivity is a chemical property that describes a substance's ability to chemically react with other materials.
Step-by-step explanation:
The ability of a substance to chemically react with other materials is referred to as its reactivity. This is an example of a chemical property, which describes the ability of a substance to undergo a specific chemical change. Other examples of chemical properties include flammability and acidity. In contrast, physical properties, such as melting point, boiling point, and density, can be observed or measured without changing the identity of the substance.