What is a characteristic of a physical change?

What is a characteristic of a physical change?

• A. Alters the chemical composition of substances
• B. Involves a change in energy state only
• C. Affects physical properties without changing composition
• D. Always produces a new substance

Answer: (C)

A characteristic of a physical change is that it affects physical properties without changing the composition of the substances involved. This means that during a physical change, the substance may undergo alterations in its state or appearance—such as melting, freezing, or dissolving—but the underlying chemical structure remains unchanged. For example, when ice melts to form water, it transitions from solid to liquid, but the chemical composition of H2O remains constant throughout the process. In contrast, changes that alter the chemical composition, such as combustion or oxidation, are classified as chemical changes. Therefore, the defining feature of a physical change lies in its ability to modify aspects like shape, size, or phase while retaining the original substances intact.

A characteristic of a physical change is that it affects physical properties without changing the composition of the substances involved. This means that during a physical change, the substance may undergo alterations in its state or appearance—such as melting, freezing, or dissolving—but the underlying chemical structure remains unchanged. For example, when ice melts to form water, it transitions from solid to liquid, but the chemical composition of H2O remains constant throughout the process.

In contrast, changes that alter the chemical composition, such as combustion or oxidation, are classified as chemical changes. Therefore, the defining feature of a physical change lies in its ability to modify aspects like shape, size, or phase while retaining the original substances intact.