Which movement of gases in cells should occur for the burning of food and the release of energy? A. oxygen in and carbon dioxide in
B. oxygen in and carbon dioxide out
C. oxygen out and carbon dioxide in
D. oxygen out and carbon dioxide out

4al + 3o2 → 2al2o3 what does the "3" in front of o2 stand for? a) it indicates that there are 5 oxygen atoms after you add the coefficient and the subscript. b) it indicates that that there are are total of 6 oxygen atoms all bonded together as a single molecule. c) it indicates that there are 3 oxygen molecules chemically bonded to each other in the reaction. d) it indicates that there are 3 separate oxygen molecules in the reaction.