Which chemical equation is balanced? a. h2 + o2 --> h2o b. h2 + o2 --> 2h2o c. 2h2 + o2 --> 2h2o d. 2h2 + 2o2 --> 2h2o

C.2H2 + O2 --> 2H2O

4H 2O > 4H 2O

Numbers atoms of the H and O are the same before and after reaction.

the old alchemists made significant contributions to science even though there starting premises were off a bit. their conclusions after failure would steer them into better directions for investigation. science is no more than close observation and the initial mistakes result in rethinking and retrying experiments.