Which is the layer underground where all empty spaces are filled with a combination of air and water ?

answer; ///i believe its: ///(embolus);

the answer to you question is   jet streams

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.