An apple is cut into slices. half of the slices are sprayed with lemon juice. all slices are stored in a sealed plastic bag. after 4 days, they are observed to see how brown they turned.
what’s the independent and dependent variable?

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.