Step-by-step explanation:
A property which changes chemical composition of a substance is known as chemical property.
For example, precipitation, reactivity, toxicity etc are chemical property.
A property which does not bring any change in chemical composition of a substance are known as physical properties.
For example, shape, size, mass, volume, density, etc of a substance are all physical properties.
Thus, we can conclude that reactivity is a chemical property of metal.