Which of the following is considered a physical property of matter?

• A. Ability to rust
• B. Flammability
• 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. Review the given options: 'Ability to rust,' 'Flammability,' and 'Reactivity with acid' all describe how a substance chemically reacts, so these are chemical properties.
3. Recognize that 'Melting point' refers to the temperature at which a substance changes from solid to liquid without altering its chemical composition, making it a physical property.
4. Conclude that since melting point involves a phase change without changing the substance's identity, it is classified as a physical property of matter.
5. Therefore, the correct answer is 'Melting point' because it is the only option that describes a physical property rather than a chemical property.