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

• A. Breaking a glass
• B. Rusting of iron (Fe)
• C. Melting of ice (H2O)
• D. Dissolving sugar in 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 to determine if it involves a change in chemical composition:
3. Breaking a glass is a physical change because it only changes the shape and size of the glass, not its chemical identity.
4. Rusting of iron (Fe) 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 iron.
5. Melting of ice and dissolving sugar in water are physical changes because the substances change state or mix but their chemical identities remain the same.