Which of the following is a chemical property of copper?

• A. Copper is an excellent conductor of electricity.
• B. Copper has a density of 8.96 g/cm^3.
• C. Copper is a reddish-brown metal.
• D. Copper reacts with oxygen to form copper(II) oxide.

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 a substance's ability to undergo chemical changes and form new substances.
2. Analyze each option to determine if it describes a physical or chemical property: For example, conductivity, density, and color are physical properties because they do not involve changing the substance's chemical identity.
3. Identify the option that involves a chemical change: The statement 'Copper reacts with oxygen to form copper(II) oxide' describes a chemical reaction where copper changes its chemical composition, indicating a chemical property.
4. Recall that chemical properties often involve reactivity with other substances, such as oxygen, acids, or bases, leading to new compounds.
5. Conclude that the correct chemical property of copper is its ability to react with oxygen to form copper(II) oxide, distinguishing it from the physical properties listed.