13.3 Exercise 18

A solution is saturated with silver sulfate and contains excess solid silver sulfate:
$\text{Ag}_{2} \text{SO}_{4} \left(s\right) \rightleftharpoons 2 \text{Ag}^{+} \left(a q\right) + \text{SO}_{4} ^{2−} \left(a q\right)$

A small amount of solid silver sulfate containing a radioactive isotope of silver is added to this solution. Within a few minutes, a portion of the solution phase is sampled and tests positive for radioactive Ag⁺ ions. Explain this observation.