Which of the following is a definite indicator of a chemical change?

• A. Change in the state from solid to liquid
• B. Dissolving sugar in water
• C. Change in size or shape
• D. Formation of a new substance with different properties

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 option to determine if it represents a physical or chemical change: For example, changing state from solid to liquid is a physical change because the substance's identity remains the same.
3. Recognize that dissolving sugar in water is a physical change because sugar molecules disperse but do not chemically alter.
4. Identify that a change in size or shape is a physical change since it does not involve altering the substance's chemical structure.
5. Conclude that the formation of a new substance with different properties is a definite indicator of a chemical change, as it involves a chemical reaction producing new materials.