I don't think it does

I'll go ahead and assume that what you're really asking is whether silver oxidizes or not. And, the simple answer is "yes." Of course, under the right circumstances any metal can be made to oxidize because metals generally have very weak holds on their electrons and oxygen has a very strong attraction to these electrons. Now, obviously that's not the answer you're looking for so...

Does silver oxidize very easily and rapidly like iron? Not even close. Does it oxidize as minimally as glod or platinum? Nah. But, they've got all kindsa tarnish remover products that'll clean it up for you.

I see that, today, one can buy an ounce of silver bullion for about $11. An ounce of gold is around $572. Man, that's high. Was below $300 before 2003. Iraq is killing us. Make that Bush. Price changes daily (or more frequently) with market trading.

And Mav's right, though for we say that silver "tarnishes", not "corrodes" (both terms refer to the oxidation of the metal, but in "corrosion" the damage to the metal is obvious, whereas in "tarnishing" it is not, at least in the short term). Unpolished, that silver bar will be black in a few month's time, more or less depending on how humid your atmosphere is. Ask any trumpet player with a silver horn :).