Science Person Posted February 19, 2009 Share Posted February 19, 2009 (edited) Even after twenty years of use most quarters have the same shiny appearance that they did when they were minted. Most pennies, however, have dulled considerably. What does this suggest about the position of the metal used to make quarters and the metal used to make pennies on the activity series? *Talking about quarters and pennies from 1997* Over time pennies get dull because of their composition since they are made purely made from copper and as a result copper reacts with oxygen and other gases in the air and therefore lose their shininess as copper reacts with oxygen in the air to make copper oxide and therefore turn dull however, (I am having trouble why quarters don't get dull (statistics = 1997 quarters are 99.9% nickel). And I can not determine the relationship between nickel and the fact that it does not react because it should since it is higher than copper on the acticity series. Someone please explain. Thank You Edited February 19, 2009 by Science Person Link to comment Share on other sites More sharing options...
npts2020 Posted February 19, 2009 Share Posted February 19, 2009 Although it seems counterintuitive it is a fact that the more reactive a metal is the faster it gets to its steady state surface color (which is rust or oxidized metal) and the tighter the bonding of that oxidation to the underlying metal causing the rusting to stop sooner. Tight bonding=shiny surface. A chemist might excoriate my terminology but that is the basic reason. BTW pennies are mostly zinc these days. Link to comment Share on other sites More sharing options...
jdurg Posted February 19, 2009 Share Posted February 19, 2009 Pennies are indeed mostly zinc, but the only part of a penny that is exposed to the atmosphere is copper. The zinc just makes up the core of the penny. Also, the statistics on the Quarter are off. They are nowhere near 99.9% nickel! The composition of the quarter is a core of pure copper with an outer cladding of 75% copper and 25% nickel. Overall, it's only 8.33% nickel. Link to comment Share on other sites More sharing options...
hermanntrude Posted February 19, 2009 Share Posted February 19, 2009 have a look at this... it's about US pennies, but similar Link to comment Share on other sites More sharing options...
Proplayer109 Posted March 1, 2011 Share Posted March 1, 2011 Nickel doesn't loose its shininess just as quickly because of the process called reduction. We all know that Nickel is not reactive with air (more specifically oxygen), thus when the oxygen does come in contact with the quarter it loses two electrons and goes back into the atmosphere as O+2 . Even after twenty years of use most quarters have the same shiny appearance that they did when they were minted. Most pennies, however, have dulled considerably. What does this suggest about the position of the metal used to make quarters and the metal used to make pennies on the activity series? *Talking about quarters and pennies from 1997* Over time pennies get dull because of their composition since they are made purely made from copper and as a result copper reacts with oxygen and other gases in the air and therefore lose their shininess as copper reacts with oxygen in the air to make copper oxide and therefore turn dull however, (I am having trouble why quarters don't get dull (statistics = 1997 quarters are 99.9% nickel). And I can not determine the relationship between nickel and the fact that it does not react because it should since it is higher than copper on the acticity series. Someone please explain. Thank You Link to comment Share on other sites More sharing options...
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