Final answer:
An activity series can predict whether a single-replacement reaction will occur by comparing the reactivity of the elements involved. Option a.
Step-by-step explanation:
By using an activity series, we can predict whether a certain chemical reaction will occur, specifically a single-replacement reaction. The activity series is a list of elements ranked in order of their ability to displace other elements in a compound. For example, a more reactive metal in the series can displace a less reactive metal from its compound.
To use the activity series, compare the element that may cause the displacement to the elements in the compound. If the single element is higher in the activity series than the element in the compound, then the displacement reaction is likely to occur, leading to a spontaneous redox reaction.
For instance, if magnesium (a more active metal) is introduced into a solution of copper(II) sulfate, magnesium will displace copper to form magnesium sulfate and solid copper. The balanced chemical equation for this reaction would be Mg(s) + CuSO₄(aq) → MgSO₄(aq) + Cu(s). Option a.