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

• A. A new substance is formed with different properties from the original substances.
• B. The substance changes from a solid to a liquid.
• C. The substance is broken into smaller pieces.
• D. The temperature of the substance increases without any other change.

Answer: (A)

Verified step by step guidance

1. Understand the definition of a chemical change: it involves the formation of one or more new substances with different chemical properties and compositions from the original substances.
2. Recognize that physical changes, such as changing from solid to liquid or breaking a substance into smaller pieces, do not produce new substances; they only alter the physical state or size.
3. Note that a temperature increase alone, without any other change, is a physical change and does not indicate a chemical change.
4. Identify that the best evidence of a chemical change is the formation of a new substance with properties different from the original substances.
5. Therefore, the correct choice is the one that states a new substance is formed with different properties, as this directly indicates a chemical change.