Which of the following physical changes involves a change in a substance's state of matter?

• A. Breaking a glass window
• B. Dissolving sugar in water
• C. Melting of ice to form liquid water
• D. Cutting a piece of paper

Answer: (C)

Verified step by step guidance

1. Understand that a physical change is a change in the form or appearance of a substance without altering its chemical composition.
2. Recognize that a change in the state of matter means the substance transitions between solid, liquid, gas, or plasma phases.
3. Analyze each option: Breaking a glass window and cutting a piece of paper change the shape or size but not the state of matter.
4. Dissolving sugar in water is a physical change but involves mixing substances, not changing the state of matter of sugar or water.
5. Melting of ice to form liquid water is a physical change where the state changes from solid to liquid, which is a change in the state of matter.