Why when wood burns does the remaining ash weigh less than the beginning wood, when the law of conservation is applied?

The introduction of combustion has a necessary biproduct: smoke. If you consider the conversion of the solid wood mass into both ash and all the gases and particles contained in the smoke AND you include all the that in your "closed system" according to the parameters of the Law of Conservation, then I could agree. However, the ash does not account for all matter distributed into the atmosphere by the fire.

Therefore, the ash alone would have less mass when compared with the original wood.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.