Mix magnesium and zinc oxide and there will be a displacement reaction where the magnesium takes the oxygen away from the zinc, showing that magnesium is more reactive.
How Can You Tell Magnesium Is More Reactive Than Zinc?
Take two beaker containing HCL in it.Put magnesium in one beaker and zinc in another beaker.Respective chlorides will be formed.But magnesium reacts faster than zinc hence it is more reactive