Which of the following is a physical property of copper?

• A. Copper forms a green patina when exposed to air.
• B. Copper reacts with oxygen to form CuO.
• C. Copper has a reddish-brown color.
• D. Copper can be dissolved in nitric acid.

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 the first statement: 'Copper forms a green patina when exposed to air.' This describes a chemical change (formation of a new compound), so it is a chemical property.
3. Analyze the second statement: 'Copper reacts with oxygen to form CuO.' This involves a chemical reaction producing copper oxide, so it is a chemical property.
4. Analyze the third statement: 'Copper has a reddish-brown color.' This describes an observable characteristic without changing copper's identity, so it is a physical property.
5. Analyze the fourth statement: 'Copper can be dissolved in nitric acid.' This involves a chemical reaction where copper changes into ions, so it is a chemical property.