Which of the following is a physical property?

• A. Flammability
• B. Ability to rust
• C. Reactivity with acid
• D. Melting point

Answer: (D)

Verified step by step guidance

1. Understand the difference between physical and chemical properties: Physical properties can be observed or measured without changing the substance's identity, while chemical properties describe how a substance interacts with other substances, resulting in a chemical change.
2. Analyze each option: Flammability, ability to rust, and reactivity with acid all involve chemical changes because they describe how a substance reacts and forms new substances.
3. Recognize that melting point is a physical property because it describes the temperature at which a substance changes state from solid to liquid without altering its chemical composition.
4. Conclude that among the given options, melting point is the physical property since it involves a physical change, not a chemical reaction.
5. Summarize that physical properties include characteristics like melting point, boiling point, density, and color, which can be observed without changing the substance's identity.