Hello, Ive got what some can call a simple question. When an object is burning, I know the 3 things a fire needs are energy, fuel and oxygen. When the object, lets say a sheet of paper, do the oxygen atoms combine with atoms of the paper and become the ash, soot, and smoke the results? I have a basic knowledge that there is CO2 released, which I would have to go and say that O2 combine with C during that reaction, which is part of the smoke. Does the Ash contain the oxygen that was used up by the reaction as well as the smoke?