Answer:
The fire that dragons spew is the result of the chemical reaction between limestone and fluorine.
Explanation:
There is a theory that explains that the fire expelled by dragons is the result of the chemical reaction between limestone and fluorine. This theory states that dragons eat limestone that is stored in their bodies, which already have fluorine naturally. When the dragon feels threatened, or feels that it is in a moment of attacking, it shares these two elements at the same time, which when uniting react to produce fire.