in an American currency shop
I would recommend against it as it is illegal, but you would need zinc and heat to turn a copper penny to brass.
No, bleach will not change a coins colour.
it would turn a dark color green
Chemical, since it doesn't turn back.
oxygen.
well if you put a penny in ginger ale it will turn silver
leave it water for about a week or longer, how long it takes depends on size, i would personally start with a penny.
I have a penny beside me soaking in Hydrogen Peroxide. after about half an hour it gained some small bubbles all over the penny, you would think being copper the penny would oxidize and turn green. This does not appear to be happening yet, however, it may be that the penny has an oxide protection covering it - either that or it would take more time.Why not try it your self and see?Hydrogen Peroxide is available at nearly every grocery store and I am sure you have a penny or two laying around.
It's not silver. It's a 1943 steel penny.
One cent. That's one of the most common dates for "wheaties". Over a billion were made.
Brass
It was most likely due to the combination of the Klondike Gold Rush of 1896-1899 and the Nome Gold Rush of 1899-1909.