There are lots of exterior uses for zinc. It oxidizes very easily, but the oxide coats it to prevent further oxidation. i.e. galvanized pipe that does not rust. BTW, aluminum does the same thing. It is a very good exterior material so long as it does not contact salt, but it is so reactive that it has been used as rocket fuel. Don't believe me. Look it up. Back to copper. It is so reactive that they use it for water pipes. It is so reactive there that it lasts for decades. As for your link, I will give you no argument that copper is more reactive than most other coinage materials (except zinc and steel). However, coinage materials are selected because they are non-reactive.
That's a good point. Zinc is used on galvanized steel pipe. I hate to tell you but this pipe - with its coating of zinc - rusts like he11 on the inside, so much so that over time the pipe will not longer be able to provide adequate flow. It is similar to what happens when a person's arteries become clogged. (In the pipe it is the steel that rusts, not the zinc.) I am a home inspector and I see these clogged galvanized steel pipes all the time. I can show you a picture of one if you like. Maybe it's that the layer of corrosion provides a protective coating. I think we may have strayed from the original point I was making. I tried to make a point that copper is more reactive than other metals used in coins (except zinc - 2 points for you on that one). I was addressing primarily toning and surface spots on coins.
That was your original statement. I disagreed with the term "highly reactive" and I still disagree with it. And, no, copper does not form a coating like aluminum. Lead does, iron, steel, calcium, potassium, etc. do not.
No he's not, I saw a wiggle there Really !! Then you better get yourself down to a lab someplace because you are truly unique. "All known life on Earth is built upon carbon and carbon-based compounds. Yet the possibility has been discussed that life elsewhere may have a different chemical foundation – one based on the element silicon. " Internet Encyclopedia of Science
