Gases can be produced by normal flora (bacteria that normally lives in the intestines) and harmful bacteria as well.
Answer:
Because the mass contributed by electrons is dwarfed by the nuclear contribution. There exists three orders of magnitude difference. Electronic mass can be ignored to a first approximation.
Explanation:
the vital capacity of an athlete is higher than a non-athlete because they are trained to do hard work, their lungs get bigger over time and make it easier for them to take long breaths when they are running or doing any other exercise