Wouldn't it be water vapor? Don't quote me on this, but I think when water Molecules (H2O) heat up, they expand away from each other and become gas.
Answer:
The process that produces fuel for motor vehicles from living plant products is alcoholic fermentation.
Answer: supernova
Explanation: Massive stars, on the other hand, quickly move beyond these more light elements to create heavier elements like silicon and copper. Anything heavier than iron is created during a supernova–the star-shattering explosion at the end of a massive star's life cycle.