Final answer:
If something is quickly and easily set on fire, it's referred to as flammable, like napalm or acetylene, which have high combustion levels. Safety measures with flammable substances highlight the energy density of fossil fuels that burn without being highly explosive.
Step-by-step explanation:
If a substance is quickly and easily set on fire and burned, it is described as flammable. An example of an incredibly flammable substance is napalm, which is a type of gasoline turned into a jelly-like form and mixed with other incendiary agents to enhance its burning properties. Another example is acetylene, used in torches because of its high heat of combustion.
The combustion process is a rapid chemical reaction that combines molecules of oxygen with molecules of fuel, like carbon and hydrogen, which results in the release of energy in the form of light and heat. It is important to note that while some covalent compounds with carbon and hydrogen burn easily, many ionic compounds do not. Understanding the nature of flammable substances is important for safety. Although fossil fuels like gasoline burn, they are not typically explosive under normal conditions, which is why they are considered as having a high energy density with a significant safety aspect. The vapor of the fuel, when mixed with oxygen, is the actual component that ignites, rather than the liquid itself.