The following reaction does not proceed to a product: Cu + Al2O3 --> no reaction. Why is that?
Copper has a higher activity than aluminum and cannot replace it.
The reaction cannot occur because copper is a reactant.
Copper has a lower activity than aluminum and cannot replace it.
The reaction proceeds too slowly to create products.
I think the correct answer would be that copper has a lower activity than aluminum and cannot replace it. According to the activity series, copper is lower than aluminum therefore it could replace aluminum in reactions. Hope this helps.