Which type of property can be observed without changing a substance?

A physical property refers to a characteristic of a substance that can be observed or measured without altering the substance's chemical composition. Examples of physical properties include color, odor, boiling point, melting point, and density. When you observe these properties, the substance remains unchanged in its chemical identity.

In contrast, a chemical property describes how a substance interacts with other substances, leading to a change in its chemical structure. Observing a chemical property typically results in a transformation, such as rusting of iron or burning of wood, where the substance no longer remains the same. Similarly, reactive and intrinsic properties often pertain to chemical behavior or unique characteristics based on the substance's identity, which may also involve changes during evaluation. Recognizing the difference between these types of properties is essential for understanding material science and conducting experiments.