Vinegar added to baking soda forms a gas. Water evaporates into air. Sugar dissolves in water. Corn kernels are crushed to form flour.
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:
- Vinegar added to baking soda forms a gas.
- Water evaporates into air.
- Sugar dissolves in water.
- Corn kernels are crushed to form flour.

Could you tell me which one is correct?

Vinegar added to baking soda forms a gas.