In which situation can a mixture always be called a solution? when one of its components is a gas when there is no solvent in the mixture when its components are made up of different types of particles when the mixture is homogeneous

the answer is D on ed  

Explanation:

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."

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.