How many oxygen atoms are there in the following compound: 2hno3
3
5
6
12

6

Explanation:

There is 2 of the coumpond, in one compound, there are 3 oxygens. But when there are two, it is 6.

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.

the answer would be c