Physical Properties:
weight: before 1982 a penny weighed 13.1 g and after 1982 it weighed 12.5 g. The reason for this weight difference is because the composition is different between 1982 and present day pennies. Pennies made from 1944-1982 were made out of 95% copper and 5% zinc. Pennies made from 1982-2010 are/were made out 2.5% copper and 97.5% zinc. Thus concluding copper is heavier than zinc.
volume of 1982-2010 pennies: 360mm3.
color: copper brown
circumference: 19mm
smell: copper iron smell (alike blood)
density: pre 1982: 3.11g post 1982: 2.50g
diameter: 19mm
radius: 9.5mm
Discovering Chemical Properties through making Chemical Reactions
In our third experiment we decided to soak the pennies in water and leave them over night. Both rusted however, the older penny rusted mores so than the newer one.
For the fourth experiment we soaked the pennies in jewelry cleaner which polished both pennies. Who knew that underneath all that dirt the older penny was almost as shiny as the 2010 penny?
Our last and final experiment is somewhat incomplete. We had heard that if you soaked a penny in coke that eventually the penny would disintegrate and be "eaten" completely by the coke. Fascinated by that we tried it. We discovered that after a day of soaking not much had change. We think that there was a slight change in the size and shape of the penny, but we are unsure if the change was accurate. Katherine and I plan to continue the coke experiment, because we feel that over time it will eventually happen, and we are determined to discover the answer.
Work Cited:
http://www.usmint.gov/about_the_mint/fun_facts/?flash=yes&action=fun_facts2
http://webapps.monroe.edu/technologyservices/multimedia/guides/3255c.pdf