The project that I made, consisted in cleaning up old and dirty pennies. For cleaning up, I used a variety of materials such as lemon, vinegar and salt, water, water with soap. Before starting the experiment, I made a hypothesis based on the background information so I can see which ingredient will have more efficiency. What I predict was that vinegar mixed with salt will have a greater impact on cleaning pennies. After finishing the experiment, my results did support my hypothesis. The ingredient that had more impact was vinegar and salt because in the process of the experiment, the mixture start making bubbles, which in the other mixtures did not happen. Also, the mixture start becoming more dark and when I took out the pennies and dry them, the dirty was removed very fast and easily. In the other mixtures, there were no extreme changes and the reactions of the mixtures were not the same as the one with vinegar and salt. Some recommendations I provide is that before you start the experiment, collect pennies that are dirty but have the same dirtiness so you can have an exact evidence of which had more impact. Since this was an easy experiment, it was easy to follow steps and so, I do not committed much errors. In conclusion, this experiment made me see how strong vinegar mixed with salt is and how the impact was in a variety of ingredients.