You were driving through the great plains of nebraska to northern idaho. gradually, the grassland gave way to tall conifers. through which biomes did you travel?

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.