Which of the following does NOT describe a physical property of iron?

• A. Iron is magnetic.
• B. Iron is a solid at room temperature.
• C. Iron reacts with oxygen to form rust.
• D. Iron has a melting point of 1538 °C.

Answer: (C)

Verified step by step guidance

1. Step 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 interacts with other substances, resulting in a change in composition.
2. Step 2: Review each statement to determine if it describes a physical or chemical property of iron.
3. Step 3: Analyze 'Iron is magnetic.' Magnetism is a physical property because it describes how iron responds to a magnetic field without changing its chemical identity.
4. Step 4: Analyze 'Iron is a solid at room temperature.' The state of matter at a given temperature is a physical property because it does not involve a chemical change.
5. Step 5: Analyze 'Iron reacts with oxygen to form rust.' This describes a chemical reaction where iron changes composition by forming a new substance (rust), so it is a chemical property, not a physical property.