Which type of soil is likely to have the lowest porosity

metamorphic rocks, which formed under great pressure, have the lowest.

what's the rest of the question

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.