Which observation most likely indicates that only a chemical change has taken place?

• A. Ice melts into liquid water.
• B. Water evaporates from a puddle.
• C. A solid is broken into smaller pieces.
• D. A new substance with different properties is formed.

Answer: (D)

Verified step by step guidance

1. Understand the difference between physical and chemical changes: Physical changes affect the form of a substance but not its chemical composition, while chemical changes result in the formation of new substances with different properties.
2. Analyze each observation to determine if the substance's chemical identity changes: For example, melting ice or evaporating water involves phase changes but the chemical formula H\_2O remains the same.
3. Recognize that breaking a solid into smaller pieces is a physical change because the substance's chemical structure does not change.
4. Identify that the formation of a new substance with different properties indicates a chemical change, as this means the original substances have undergone a chemical reaction.
5. Conclude that the observation 'A new substance with different properties is formed' most likely indicates a chemical change because it reflects a change in chemical composition.