Which of the following is an example of a physical change?

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

Answer: (B)

Verified step by step guidance

1. Understand the difference between physical and chemical changes: A physical change affects the form or physical properties of a substance without changing its chemical composition, while a chemical change results in the formation of new substances with different chemical properties.
2. Analyze each option to determine if the chemical composition changes: Digestion of food involves breaking down complex molecules into simpler ones, which is a chemical change.
3. Burning of wood involves combustion, producing new substances like ash, carbon dioxide, and water, indicating a chemical change.
4. Rusting of iron is a chemical reaction between iron and oxygen forming iron oxide, which is a chemical change.
5. Melting of ice changes the state of water from solid to liquid without altering its chemical composition (H2O remains H2O), so it is a physical change.