When I want to prevent iron from rusting, I use a more reactive metal such as magnesium and connect it to the iron. This protects iron from being rusted as the magnesium will transfer electrons into the iron when it rusts, thus reducing Fe2O3 into Fe metal. However, Mg will be oxidised to Mg2+ but how does it get oxidised? It's electrons are transferred to the Fe2O3 already, so how does a layer of MgO form around it? Since ionic compounds form when the electrons transfer from the metal to the non metal (layman terms) so hoe does the magnesium receive its oxygen ion? Also, I thought a lot of heat is required for Mg to displace Fe2O3? So why just a wire is needed for it to "cure" the metal. And why can't we extract iron ore Fe2O3 from this method too? Lastly, if I place a wire onto a zinc block and dip the other end of the wire into a solution of copper sulfate, will displacement of the metal occur to form copper metal in the solution while the since forms a block of Zn2+ ions? Thanks for the help!