Which of the following statements describes a chemical property?

• A. Iron reacts with oxygen to form rust.
• B. Water boils at 100^ext{o}C.
• C. Copper is a good conductor of electricity.
• D. Ice melts at 0^ext{o}C.

Answer: (A)

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. Analyze each statement to determine if it involves a change in the substance's chemical identity or just a physical change.
3. The statement 'Iron reacts with oxygen to form rust' describes a chemical change because it involves iron combining with oxygen to form a new substance (rust), indicating a chemical property.
4. The other statements describe physical properties: boiling point of water, electrical conductivity of copper, and melting point of ice, all of which do not involve changing the chemical identity of the substances.
5. Therefore, the statement that describes a chemical property is the one involving iron reacting with oxygen to form rust.