Which of the following statements about moles is correct?

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.

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

1 is the answer to this problem