1. Project title: DIRTY PENNY CLEAN Student Name: Jacob Aryee
STEM Fair Project
Project title: DIRTY PENNY CLEAN
Student Name: Jacob Aryee

2. Statement of the Problem
Which solution will clean a dirty penny better?

3. 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

4. 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

5. 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.

6. Materials 3 dirty pennies 3 plastic cups Water A teaspoon
Arm & Hammer Free & Clear laundry detergent
White vinegar
Salt
Arm & Hammer baking soda

7. 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

8. 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.

9. 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.

10. Detergent
Water!
Detergent!

11. Detergent Results BEFORE AFTER
Not bad. But let’s see if we can get it cleaner!

12. Baking Soda
Mixing!
Baking Soda!

13. Baking soda Results
BEFORE
AFTER
WONK WONK WONK 
An epic fail!

14. Vinegar & SALT
Salt!
Vinegar!

15. Vinegar & Salt Results
BEFORE
AFTER
Look at that shine!

16. Works Cited
Interesting Egg Fact.