A teacher wants to perform a classroom demonstration that illustrates both chemical and physical changes. Which would be the best demonstration that she could use?

Burning a candle shows both types of change. The wax melts, which is a physical change because it changes state but remains wax. The wick and wax vapor also burn and form new substances, which is a chemical change. Bending aluminum, breaking a matchstick, and dissolving sugar are physical changes only.

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