IS FIRE A MATTER?
Before I jump into my today's article I would like to break the topic and talk about fire and matter singly before entering the topic of the day.

SOLID: they have a definite shape,volume. The molecules transition around their main position, they can also change states from solid to liquid(melting)and from liquid back to solid which is known as freezing. Solid can also change state directly to gaseous state which is known as (sublimation) but can't move directly from gaseous state to solid state without going through liquid.

LIQUID: it's an incompressible liquid that takes the shape or its container but, retains a constant volume and no fixed shape. Liquid changes state varyingly from liquid to solid (freezing) ,solid to liquid(melting) , liquid to gaseous ( evaporation), and gaseous back to liquid (condensation). 
GAS: they spread apart to fill containers, unlike liquid and solid. They have no fixed shape or volume and low density. When heated they get excited and bounce around its containers. 
Thus, looking for an explanation for why fire is a matter is somewhat absurd in that absurd. Science study and explain what we do not understand. For a certain substance to be called matter it must possess weight(mass) and occupy space.
Fire can't be contained indefinitely as long as reactant particles are present(oxygen,fuel,orsubstance that causes effective burning).
More so, fire comprises of various gases leading to combustion which eventually librates various gases ,chemical reactiin, light and heat. Personally I think fire is a matter because it could be seen which means it occupies space and it's a mixture of gases which has a certain mass or volume.
Drop your comment if you think otherwise thanks for reading.
Great post 👏👏