Which of the following is a physical property of copper?

• A. Copper reacts with hydrochloric acid to produce hydrogen gas.
• B. Copper can be oxidized to form CuO.
• C. Copper has a reddish-brown color.
• D. Copper forms a green patina when exposed to air.

Answer: (C)

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 reacts to form new substances.
2. Analyze each statement to determine if it describes a physical or chemical property:
3. - 'Copper reacts with hydrochloric acid to produce hydrogen gas' describes a chemical reaction, so it is a chemical property.
4. - 'Copper can be oxidized to form CuO' involves a chemical change (oxidation), so it is a chemical property.
5. - 'Copper has a reddish-brown color' describes an observable characteristic without changing the substance, so it is a physical property.