How do scientists use the doppler effect to measure the actual motion of stars?

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.

yes it is   dangerous

explanation:

because that foot is discusting and could get you sick