It is completely destroyed. It is completely changed into heat energy. It changes into other types of matter and energy. It physically changes into the gaseous phase.
I gave my students this multiple choice question: What happens to a wooden log when it is burned?

Only one answer is correct among these 4 choices:
- It is completely destroyed.
- It is completely changed into heat energy.
- It changes into other types of matter and energy.
- It physically changes into the gaseous phase.

Could you tell me which one is correct?

It changes into other types of matter and energy.