Which of the following best describes a chemical property?

• A. The density of mercury
• B. The color of copper metal
• C. The melting point of ice
• D. The ability of iron to rust when exposed to oxygen

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 a chemical change.
2. Examine each option to determine if it involves a change in the substance's chemical identity:
3. - Density of mercury: This is a physical property because it describes mass per unit volume without changing mercury's identity.
4. - Color of copper metal: This is a physical property as it relates to appearance without altering the substance chemically.
5. - Melting point of ice: This is a physical property since melting changes the state but not the chemical composition of water.
6. - Ability of iron to rust when exposed to oxygen: This is a chemical property because rusting involves iron reacting with oxygen to form a new substance (iron oxide), changing its chemical identity.