what are the effects of oxygen on medal.
5 answers
On medal or metal?
medals like an olympic metal
What kind of metal is used for Olympic medals?
http://chemistry.about.com/od/metalsalloys/f/what_are_olympic_medals_made_of.htm
On the gold medals that outside layer is gold plated and oxygen will have little effect on it. For the silver medals, oxygen will tarnish silver over time forming either silver oxide or silver sulfide or both (think household silverware made with silver or silver plate--the silver must be "polished" now and then.) Bronze darkens on long exposure to oxygen due to the formatiion of copper oxide..