Which major environmental factors can affect health?

genetics and obesity
poor water quality and obesity
poor air and water quality
genetics and poor air quality

The answer is poor air quality and water quality

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.