[Science Experiment] Can oxygen be used up to 0% ? I think I did an experiment when I was in elementary school about things such as candles that "burn". The following learning and experiments appear in textbooks in science in the sixth grade of elementary school. · Burn the candle in a closed bottle. · Investigate changes in gas before and after burning. · Oxygen is decreasing and carbon dioxide is increasing. · It can be seen that "oxygen" is used for combustion and "carbon dioxide" is generated. With this kind of flow, do you even remember how much oxygen is decreasing and how much carbon dioxide is increasing? Actually, it looks like the table below. Before burning After burning oxygen About 21% Abo...