Ernest Shackleton's South! primarily uses the writing structure of "problem and solution".
I'm not sure about 2 but in 3 it would float
you have to show us the rest of it because we have no idea what your looking at. I'm sorry
Answer:
carbon dioxide is a gas so it isn't collected over water.
Explanation:
it works for insoluble gases such as hydrogen,or gases that do not dissolve easily in water such as ammonia and chlorine are readily soluble in water and are not collected this way.
hope it is helpful for you.
Quantum Mechanical model (as per my knowledge)