Propane is a gas used in gas grills to cook food. During this process, the propane molecules undergo combustion with oxygen molecules to produce water and carbon dioxide and a large amount of heat is released. Which statement best describes this process?
1) Propane molecules combine with oxygen molecules to produce water and carbon dioxide.
2) Propane molecules break down into water and carbon dioxide when exposed to heat.
3) Propane molecules release heat when they react with oxygen molecules.
4) Propane molecules convert into water and carbon dioxide during combustion.