Which of the following processes is considered a chemical change?

• A. Melting of ice
• B. Rusting of iron
• C. Breaking a glass
• 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 process given: Melting of ice involves changing solid water to liquid water, which is a physical change because the chemical composition (H2O) remains the same.
3. Breaking a glass is a physical change because the glass is only changing shape or size, not its chemical identity.
4. Boiling of water is a physical change where liquid water turns into steam, but the chemical composition remains H2O.
5. Rusting of iron is a chemical change because iron reacts with oxygen and moisture in the environment to form a new substance, iron oxide (rust), which has different properties from pure iron.