Which of the following describes a physical property of copper metal?

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

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 option to determine if it involves a change in the substance's identity (chemical change) or just an observable characteristic (physical property).
3. Option 1: 'Copper can be dissolved in nitric acid' involves a chemical reaction where copper changes into ions, so this is a chemical property.
4. Option 2: 'Copper forms a green patina when exposed to air' describes a chemical change where copper reacts with elements in the air to form new compounds, so this is a chemical property.
5. Option 3: 'Copper has a reddish-brown color' describes an observable characteristic without changing copper's identity, so this is a physical property.