Science Buddies: "Ask an Expert"

HI, i have a question regarding my science fair project, im doing a project about which kind of sodas can tarnish the coin? Also i came up with the idea for the independent variable will be the types of sodas, and i planning my dependent variable will be the scales of cleaness from 1-10 but im not sure if it will work or not for my graph . can someone give me some ideas? and oh which is an appropiate site that i can get some info/sources for my science fair.
SOrry for posted in a wrong place, because i dont know where i can create a new topic so i just posted in here
REPLY ME SOON PLZ :]

Hi,

To get a new topic, you can just press the 'Newtopic' button at the top left of the forum. But I have split off your answer and moved it to the physical sciences forum, because this is a chemistry question. The experts here should be able to help you better.

Good luck!