Final answer:
Fire is a physiochemical process that rapidly releases energy via the oxidation of organic compounds. It requires three key factors to cause combustion: oxygen, fuel, and ignition. Fire cannot occur when atmospheric oxygen levels fall below 13% and is limited by fuel moisture under current oxygen levels.
Step-by-step explanation:
The element of fire can be considered a physiochemical process that rapidly releases energy via the oxidation of organic compounds. Fire is often summarized in a classic "fire triangle" made up of the three key factors to cause combustion: oxygen, fuel, and ignition. Fire cannot occur when atmospheric oxygen levels fall below 13% and under current oxygen levels (21%), fire activity is limited by fuel moisture.