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world gathers for metal finishing
Q&As since 1989


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Cleaning pennies for a Science Project

My 9 year old son is performing his 4th grade science project on the ability of different cleansing agents to "Clean" pennies. We already did the experiment, using water, salt water, root beer, ammonia, bleach, vinegar [in bulk on eBay or Amazon], copper cleaner, lemon juice, and dish washing liquid. I'm sure you know the results: copper cleaner, lemon juice, ammonia [on eBay or Amazon] worked best.

Can you give us a little help by describing the chemistry of tarnish and its removal in terms that a 4th grader can understand?

Thank you for your help.

Richard I [last name deleted for privacy by Editor]
- East Northport, New York
1999

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Ed. note: Please see our F.A.Q. on the subject, Richard -- I think it will explain all, in terms that a 4th-grader, with your help, will be able to understand.

WHAT HAPPENS WHEN YOU PUT A PENNY IN BLEACH.

MICHELLE M [last name deleted for privacy by Editor]
- New York
2003

Usually you end up getting bleach on your fingers or your rubber gloves, Michelle, accidentally drying them on your slacks or the tablecloth, and leaving big white blotches on everything. Plus it is very dangerous to mix bleach with anything else, and kids may not realize that. Depending on grade, I don't think kids should use bleach in science experiments :-)

As for the effect of the bleach on the penny, what did you observe or think you observed? We'll be happy to comment on your findings. Is it was a post-1982 penny it may have almost completely dissolved.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2003

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Note to students with science projects: Please see our FAQ on Cleaning Pennies; it will tell you everything you need to know!

I'm doing a similar project. When I used bleach it basically turned it green.

Donna B [last name deleted for privacy by Editor]
- Lebanon, Virginia
March 4, 2009