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How can you tell the difference in penny compositions?

2004

A question in my science class is what year did the US Mint begin to make pennies out of zinc and copper. I found on a historical website that the year was 1943 then again in 1982. My question is, is there a scientfic/chemical way of showing or finding the difference in the different compositions.

Thank you,

Fellicia G.
student - Pueblo West, Colorado, USA

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2004

Plain old visual is the easiest way. The WWII penies look like steel. The normal penny (old) is solid copper (alloy). The modern penny is a "clad" one. Cut part of it off and you can easily see the zinc center with the copper coat.

James Watts
- Navarre, Florida