Final answer:
Reactivity with oxygen is a chemical property, as it involves a substance's ability to undergo a chemical reaction and change into a different substance.
Step-by-step explanation:
The type of property that reactivity with oxygen represents is a chemical property. This kind of property is characterized by a substance's ability to change into a different substance. For instance, iron combines with oxygen in the presence of water to form rust, which is a chemical reaction. Similar to iron’s rusting, any reactivity with oxygen, such as the tarnishing of silver or the burning of wood, indicates a chemical property. Physical properties, by contrast, involve changes that do not alter the chemical nature of a substance, such as melting point, boiling point, and density. Thus, when we refer to reactivity with oxygen, we are referring to a substance’s inherent tendency to engage in a chemical reaction with oxygen, which is a classic example of a chemical property.