How does galvanizing protect steel from corrosion?

Question

I've read and reread the small passage in the textbook about galvanising but I just still don't get it!!

It says, "The thin layer of the more reactive zinc metal coating the steel object slowly corrodes and loses electrons to the iron, thereby protecting it."

I don't get how the zinc loses electrons to the iron, how the whole thing works. If someone can please explain it to me in a simpler way, that'l be great!

Thank u sooo much!!!

Answer 1

The corrosion of iron or zinc is a chemical reaction with oxygen.  Because zinc is more reactive (with oxygen) all of it must be used up before steel is attacked (like ants eating all the frosting off a cake before bothering with the cake).  A battery cell can include plates of different metals suspended in a (wet) eloctrolyte and that can generated a current (of electrons) in an external circuit connecting the plates.  Usually only one of the plates is eaten up in the process (the zinc in a galvanized steel plate).