Which of the following represents a chemical property?

A chemical property describes how a substance interacts with other substances, leading to a change in its chemical structure. The reactivity of a substance with oxygen is a prime example of such a property, as it pertains to how the substance can undergo chemical reactions, such as oxidation. When a substance reacts with oxygen, it often forms new substances, exemplifying a fundamental characteristic of chemical behavior.

In contrast, the ability to conduct electricity, the color of a substance, and the melting point are all physical properties. These properties can be observed or measured without changing the substance's chemical structure. Conductivity refers to the physical property of a material's ability to transmit electric currents, color pertains to the light reflections from a material, and melting point describes the temperature at which a substance transitions from solid to liquid without altering its chemical identity. These examples illustrate physical changes, not chemical reactions.