Everything in the universe is made of? 1) matter 2) chemistry 3) properties

it has one origin of replication, but it proceeds in two directions - d)

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.