A Formula Counts Atoms. A Percent Weighs Them.

Carbon dioxide is 73% oxygen — and also 67% oxygen. Both numbers are right, for the same molecule, on the same day. Watch the two bars disagree, learn which question each one answers, and pick up the one signal that tells you a ratio isn't finished yet.

8 STEPS · 6 QUICK CHECKS · C = 12, H = 1, O = 16, P = 31 g/mol · v1