Final answer:
In liquid fuels, ignition leads to vaporization, which is the transition of the fuel from liquid to gas. Combustion is a chemical process that releases energy, and it begins with a thermal event marked by increased temperature. During melting and vaporization, matter transitions to a higher energy state.
Step-by-step explanation:
The ignition process in solid fuels causes pyrolysis, which is the thermal decomposition of materials at elevated temperatures in an inert atmosphere. In liquid fuels, ignition leads to vaporization, where the liquid fuel transitions into a gaseous state that can mix with oxygen for combustion. Combustion is a chemical reaction that combines oxygen with fuel molecules, releasing energy in forms such as light and heat. This chemical process begins thermally, characterized by a significant rise in temperature. In phase changes, matter undergoes a transition to a more energetic state during melting and vaporization, as energy is absorbed for the transition.