Which liquid cleans pennies the best?

1. Which liquid cleans pennies the best? 5th Grade Science Fair Project

2. Problem • Which of the five liquids used will make these pennies the cleanest and shiniest?

3. Purpose • To determine which liquid will make the pennies the cleanest.

4. Hypothesis • The penny cleaned with cola will be the cleanest.

5. Research • Before 1982, pennies were made of pure copper. • After 1982, pennies are made of zinc core with a thin copper plating. • Pure copper pennies look dirty because the copper mixes with the oxygen in the air and makes copper oxide. • All 5 pennies I am using are from before 1982.

6. Materials • ½ cup measuring cup • 5 clear plastic cups & 5 pennies • ½ cup of each liquid: coffee, cola, grapefruit juice, banana pepper juice & pickle juice • bowl of clean tap water • Pen, marker, paper & camera

7. Procedure/Experiment • Pour ½ cup of each liquid into clear cups • Take picture of pennies before dropping into liquids • Drop one penny into each cup of liquid • Wait 15 minutes • Take each penny out and rinse in bowl of clean tap water • Take picture of clean pennies after rinsing • Take notes of which is the cleanest, next to cleanest and etc…

8. Procedure/Experiment

9. Results

10. Results Best to worst: • banana pepper juice • kosher dill pickle juice • grapefruit juice • cola • coffee

11. Conclusion • My hypothesis that the cola would clean the penny the best was incorrect. In fact, the cola was in 4th place as a cleaner. My project clearly shows the banana pepper juice was the best cleaner. The pickle juice in 2nd place did a better job than the 3rd place grapefruit juice. And last, I saw no change on the penny that was in the 5th place coffee.