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

• A. Breaking a glass window
• B. Dissolving sugar in water
• C. Melting ice into liquid water
• D. Burning a piece of magnesium ribbon

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. Breaking a glass window is a physical change because the glass is only broken into smaller pieces, but its chemical structure remains the same.
4. Dissolving sugar in water is a physical change because the sugar molecules disperse in water but do not chemically react or change their structure.
5. Melting ice into liquid water is a physical change because it involves a phase change from solid to liquid without altering the chemical identity of H2O.
6. Burning a piece of magnesium ribbon is a chemical change because magnesium reacts with oxygen in the air to form magnesium oxide, a new substance with different chemical properties.