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

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

Answer: (C)

Verified step by step guidance

1. Understand the difference between a chemical change and a physical change. A chemical change results in the formation of new substances with different properties, while a physical change affects the form or state of a substance without changing its chemical identity.
2. Analyze each option to determine if it involves a chemical change: Rusting of iron involves iron reacting with oxygen to form iron oxide, which is a new substance, so it is a chemical change.
3. Digestion of food involves breaking down complex molecules into simpler ones through chemical reactions, producing new substances, so it is a chemical change.
4. Burning of wood is combustion, where wood reacts with oxygen to produce new substances like carbon dioxide and ash, so it is a chemical change.
5. Melting of ice is a change from solid to liquid water, which does not alter the chemical composition of H2O, so it is a physical change and NOT a chemical change.