Which of the following is NOT an example of a chemical change?

• A. Melting of ice
• B. Digestion of food
• C. Rusting of iron
• D. Burning of wood

Answer: (A)

Verified step by step guidance

1. Understand the difference between a physical change and a chemical change. A physical change affects the form of a substance but not its chemical composition, while a chemical change results in the formation of one or more new substances with different properties.
2. Analyze each option to determine if it involves a change in chemical composition:
3. Melting of ice: This is a phase change from solid to liquid water. The chemical composition (H\_2O) remains the same, so this is a physical change.
4. Digestion of food: This process breaks down complex molecules into simpler ones through chemical reactions, changing the chemical composition, so it is a chemical change.
5. Rusting of iron: This involves iron reacting with oxygen to form iron oxide, a new substance, indicating a chemical change.
6. Burning of wood: Combustion breaks down wood into gases, ash, and other substances, changing its chemical composition, so it is a chemical change.