What would the control group in an experiment to see what liquid cleans pennies best?

Also, info on how to perform the experiment would be very useful!! :)|||You state what liquid you think may work the best based upon some research.

You come up with what chemicals you wish to test. You will want to test multiple coins in the same solution but in different containers so 1 will not effect another.



Your controls would be,

Same amt of liquid in each container

same exact container to hold the liquid

same type coin with roughly the same amount of tarnish/dirtiness

same condition each container must sit in (i.e. keep them all together in 1 spot in the same temp, same amt of light, etc.)

same length of time in the liquid



Controls are the things to keep the same for everything you are doing so you can rule out any differences, like say you use 2 different type of containers, you wouldn't know if it was the chemical or the container that made the difference, so keep as much the same as possible, you control this aspect.|||For the control, I would soak the pennies in water. All the pennies need to be tarnished about the same amount. I've heard that vinegar cleans pennies. Alot of condiments have vinegar in them- ketchup, Texas Pete, salsa. I would use some of those and then maybe do some commercial cleaners, too -like windex, dish soap, fantastic. Soak all the pennies in the solutions for the same amount of time and then compare results to the control and to each other.



Good Luck