Re: what is a pennny made out of

I had answered this question earlier and don't know whether this is a repeat, 
but the answers you are looking for are contained in a web-site on the history 
of the United States Penny.

Try using the search terms

  +united_states +penny

http://www.pennies.org/history/intro.html

The metal in the pennies you are most likely to have are made of 95% copper and 
5% zinc, if made before 1982, and 95% zinc and 5% copper if made after 1981.  
For the pennies response to cleaning solutions, however, expect the later to 
respond as pure copper since the newer pennies are zinc wafers encased in a 
layer of copper.  If you have older pennies, you will want to consult the above 
web reference.

Thanks for your question.

sid