The melting of ice The grinding of salt crystals to powder The burning of wood The evaporation of water from a puddle
I gave my students this multiple choice question: Which is an example of a chemical reaction?

Only one answer is correct among these 4 choices:
- The melting of ice
- The grinding of salt crystals to powder
- The burning of wood
- The evaporation of water from a puddle

Could you tell me which one is correct?

The burning of wood