These are (hopefully) all the independent and dependent variables.
Idea 1:
Independent variable/s: The types metals used, amount of metal used and the amount of vinegar used
Dependent variable/s: Voltage produced, current produced, how bright the light bulb is and how the light bulb glows for.
Idea 2:
Independent Variable/s: The type of liquid, amount of liquid used, temperature of liquid, voltage of light bulb (if used) and the same type of pH paper used.
Dependent Variable/s: Voltage produced, current produced, how bright the light bulb is and how long the light bulb glows for.
Idea 3:
Independent Variable/s: Type of artificial sweetener, amount of artificial sweetener, concentration of artificial sweetener (i.e. liquid or crystal), temperature with water, amount of water, type of yeast and the amount of yeast.
Dependent Variable/s: The reaction with yeast.

March 10, 2010 at 10:19 PM
after months? we only got it for exactly one month
March 17, 2010 at 8:50 PM
what does this have to do with this post?