Final answer:
Student A is correct because lithium, a more reactive metal, displaces aluminum in aluminum chloride to form lithium chloride and aluminum metal.
Step-by-step explanation:
When lithium reacts with aluminum chloride (AlCl3), it leads to a single displacement reaction where lithium, being more reactive, will replace aluminum to form lithium chloride (LiCl) and aluminum will be released as a separate element. Since both lithium and aluminum are cations, the correct prediction would be that lithium will replace aluminum in the product, which aligns with Student A's claim that lithium and aluminum are both cations.
The reaction between lithium and aluminum chloride could be represented as:
3 Li (s) + AlCl3 (s) → 3 LiCl (s) + Al (s)