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

• A. Dissolving sugar in water
• B. Rusting of iron
• C. Melting of ice
• D. Boiling of water

Answer: (B)

Verified step by step guidance

1. Understand the difference between physical and chemical changes. 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: Dissolving sugar in water is a physical change because sugar molecules disperse but do not chemically alter.
3. Melting of ice is a physical change because water changes from solid to liquid without changing its chemical identity.
4. Boiling of water is also a physical change where water changes from liquid to gas, but the chemical composition remains H2O.
5. Rusting of iron is a chemical change because iron reacts with oxygen and moisture to form a new substance, iron oxide, which has different properties from elemental iron.