Final answer:
Most chemicals don't burn as liquids, it is their vapors that burn.
Step-by-step explanation:
True, most chemicals don't burn in their liquid state. It is really their vapors that burn.
When a chemical reaches its boiling point and changes from a liquid to a gas, it forms vapor. It is the vapor that combines with oxygen in the air and can ignite or burn. The vapor is usually more flammable than the liquid itself.
For example, gasoline is a liquid, but it doesn't burn in its liquid state. It is the vapors of gasoline that are highly flammable and can burn when exposed to a spark or flame.
Learn more about Chemicals and their burning properties