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

• A. Boiling of water
• B. Melting of ice
• C. Breaking a glass
• D. Rusting of iron

Answer: (D)

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 to determine if it involves a change in chemical composition:
3. Boiling of water: This is a physical change because water changes from liquid to gas, but its chemical formula (H\_2O) remains the same.
4. Melting of ice: This is also a physical change where solid water (ice) turns into liquid water without altering its chemical structure.
5. Breaking a glass: This is a physical change involving a change in shape or size, but the chemical composition of the glass remains unchanged.
6. Rusting of iron: This is a chemical change because iron reacts with oxygen and moisture to form a new substance, iron oxide (rust), which has different properties from pure iron.