The application of metals is closely related to their chemical properties. Xiao Min explored the metal fluidity of aluminum, iron and copper, and inserted aluminum sheet and iron sheet into sulfuric acid respectively.
In the metal activity sequence table, both iron and aluminum are in front of copper, which can theoretically react with copper sulfate solution to obtain metal copper, but a dense oxide film is formed on the surface of aluminum, which prevents the reaction between aluminum and copper sulfate.
So the answer is: iron is more active than copper, and iron can replace copper from its salt; Aluminum is active and reacts with t2 to form a dense oxide film, which prevents the reaction between aluminum and copper sulfate.