STATEMENT OF THE PROBLEM Which solution will clean a dirty penny better?
RESEARCH Pennies: – 30 million pennies are produced each day! – A picture of the Lincoln Memorial is on the back of the penny (since 1959) – Pennies are produced at the US Mint in Philadelphia (GO EAGLES!!!) and Denver – If former President Lincoln were alive today, he would be 202 years old
VARIABLES Controlled variables: Amount of liquid (1 cup), size of container (plastic cup), length of time in liquid (5 minutes) Independent variable: Cleaning Solution (e.g. cleaning agent added to water) Dependent variable: The cleanliness of the penny
HYPOTHESIS I predict that the pennies will clean better with the laundry detergent and water because the buttons on my jackets, jeans and shorts are always clean after my mommy washes them in the washing machine. I believe the buttons on my jackets, jeans and shorts are made of the same metal as a penny.
MATERIALS 3 dirty pennies 3 plastic cups Water A teaspoon Arm & Hammer Free & Clear laundry detergent White vinegar Salt Arm & Hammer baking soda
PROCEDURE Collect 3 dirty pennies Place dirty penny in cups A, B and C Pour 1 cup of water into plastic cup A Pour 1 teaspoon of laundry detergent into cup A and stir Pour 1 cup of water into plastic cup B Pour 1 teaspoon of baking soda into cup B and stir Pour 1 cup of white vinegar into cup C Pour a teaspoon of salt into cup C and stir Allow each penny to soak in the solution in each cup for 5 minutes Remove pennies from each cup carefully and inspect cleanliness of pennies Record Data
DATA/OBSERVATIONS Note: To measure, we decided to come up with our own scale to show the effectiveness (how well) of the solutions. 1 is the highest and simply means the solutions did in fact clean a good portion of the penny. 0 indicates that the solution did not alter the appearance of the penny.
CONCLUSION The results indicated that vinegar and salt was the best cleaning solution for cleaning a dirty penny. I thought that detergent would work since it cleans my dirty clothes and my buttons are always clean after washing. But detergent didn’t really make the penny very clean. With the salt and vinegar solution, 1 side of the penny became really shiny. The other side got shinier too, but it also developed a black mark which was strange.
DETERGENT Water ! Detergent !
DETERGENT RESULTS BEFORE AFTER Not bad. But let’s see if we can get it cleaner!
BAKING SODA Baking Soda ! Mixing!
BAKING SODA RESULTS BEFORE AFTER WONK WONK WONK An epic fail!
VINEGAR & SALT Salt ! Vinegar !
VINEGAR & SALT RESULTS BEFORE AFTER Loo k at that shi ne!