New matter was created in the bubbles. Old matter was destroyed as the water turned to gas. Matter was conserved when it changed form. The composition of the matter changed.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: A group of students observed the formation of bubbles when water boiled. What happened to matter because of the physical change to the water?
Possibilities:
- New matter was created in the bubbles.
- Old matter was destroyed as the water turned to gas.
- Matter was conserved when it changed form.
- The composition of the matter changed.

Matter was conserved when it changed form.