When you exercise, your body needs more what to be transported to your muscle cells to make what?

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.

the answer is c. it will give up it's valence electron to the other atom.