Which of the following best indicates that a chemical change has occurred?

• A. Breaking a glass into smaller pieces
• B. Formation of a precipitate when two solutions are mixed
• C. Dissolving sugar in water
• D. Melting of ice into liquid 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 represents a physical or chemical change:
3. - Breaking a glass into smaller pieces is a physical change because the glass's chemical composition remains the same.
4. - Formation of a precipitate when two solutions are mixed indicates a chemical change because a new solid substance forms from the reaction of dissolved ions.
5. - Dissolving sugar in water and melting ice into liquid water are physical changes because the substances retain their chemical identities despite changes in state or form.