I need to know what is my control group for my project?

I am in 5th grade and am doing a science fair project. my key question is Which will rust a penny faster, coke or mountain dew? In this question what is my control group? Please tell me before friday because that is when the project is deu!!!!!!!!|||I think it would be a third one that you dump in a glass of water. A control group is the group that doesn't get any treatment. For instance if the flowers are growing outside my house in the sun without fertilizer, those would be the control group - no change from normal and it's what you compare the experiment to to measure the results of your experiment to see how much you affected the change. An example:


My flowers grow in my garden with out fertilizer at 1/2 inch a month. The experiment then would be to see whether fertilizer A or B worked better. If the regular group grows 1/2 inch in a month, and the A group now grows 1/4 inch in a month (which means it grew slower than the control group w/ no fertilizer and therefore didn't help growth) and the B fertilizer group grew 1 inch, I have all three measurements but know A wasn't good b/c it was slower than the plants that didn't get any fertilizer at all. The only problem w/ your experiment is that the control group - no exposure group - is hard b/c I think it is going to take a long time to get a penny to rust in any of those things.|||Your controal group is what the faster is being measured against so it would be just a penny.|||A control group is a group that doesn't receive any treatment at all. Therefore, a control group in your case would be a penny that is not soaked in coke or mountain dew.





p/s: if it's possible, could u post the results here. it would be interesting to know...|||The control group in your case would be the "normal" scenario, so just how fast a penny rusts while exposed to air.|||i dunno, i think it should be water. Water and oxygen causes rust, and water has oxygen|||since you are dunking the pennies in a liquid mixture of water + whatever is in mountain dew and coke, I would say the control group would be a penny in distilled water. Make sure it's distilled, because you don't want the chemicals from your tap water to interfere with your experiment. If you have a science lab in your school ask if they have any.