using heat to burn a log in a fireplace using light to produce sugar in plants a cake that was baked from many ingredients a bottle that was broken into many small pieces
I gave my students this multiple choice question: As part of a study, a scientist observed a number of different molecular changes in matter. Which of the following observations provides evidence of a physical change?

Only one answer is correct among these 4 choices:
- using heat to burn a log in a fireplace
- using light to produce sugar in plants
- a cake that was baked from many ingredients
- a bottle that was broken into many small pieces

Could you tell me which one is correct?

a bottle that was broken into many small pieces