The mass in a chemical reaction is found

a. the energy produced by the reaction
b. the explosion produced by the chemical reaction
c. the atom involved in the chemical reaction.
d. the bonds involved in the chemical reaction.

I believe the answer is A. and correct me if i'm wrong:)

Particle exchange energy though elastic collision , hope this .

There is no reason to think the results are biased or not conducted properly but you should not assume the results are correct just because they were done in a laboratory so the answer would be c. it is likely to be reliable because the results support the conclusion presented.