Which of the following is evidence of a chemical change?

• A. Breaking a glass into smaller pieces
• B. Melting of ice into liquid water
• C. Formation of a gas when two solutions are mixed
• D. Dissolving sugar in water

Answer: (C)

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. 1. Breaking a glass into smaller pieces is a physical change because the glass's chemical composition remains the same.
4. 2. Melting of ice into liquid water is a physical change because it involves a change of state without altering the chemical identity of H\_2O.
5. 3. Formation of a gas when two solutions are mixed indicates a chemical change because new substances (gas) are produced, showing a chemical reaction has occurred.