Robert Boyle did not believe that water was one of the basic elements that all substance was made of. To test this, he conducted an experiment where he ran an electric current through water. He placed two test tubes
above each of the terminals of the electricity source and collected the gas that came out. He repeated the
experiment a total of three times, each time using the same amount of water and the same level of electric
current. These are his experimental results: what is the dependent variable in this experiment