Final answer:
In the given reaction A (<-->) B + C, a small amount of radiolabeled B is added to the solution. After a period of time, the radiolabel will most likely be found in both A and B.
Step-by-step explanation:
In the given reaction A (<-->) B + C, a small amount of radiolabeled B is added to the solution. After a period of time, the radiolabel will most likely be found in both A and B. This is because the reaction is a reversible reaction, indicated by the double-headed arrow (<-->) in the equation. In a reversible reaction, reactants can form products, but products can also react to form reactants again. Therefore, the radiolabel can distribute between A and B as the reaction proceeds.