Reactivity is a chemical property. It refers to the ability of a substance to undergo a chemical change or reaction. This property depends on the substance’s chemical composition and structure, which determine how it interacts with other substances.
For example, the reactivity of metals like sodium or potassium with water is a chemical property because it involves a chemical reaction that produces new substances, such as hydrogen gas and a metal hydroxide.
In contrast, physical properties are characteristics that can be observed or measured without changing the substance’s chemical identity. Examples include color, density, and melting point.
Understanding whether a property is physical or chemical helps in predicting how substances will behave under different conditions and in various applications.