VARIABLES

The independent variable is the variable that we change in the experiment, so in this experiment what we are going to change is the substances used to the see their properties (to see their different surface tension).

Dependent variable will be the volume of surface tension, because is the variable in the experiment that changes by changing the independent variable so if we add different substances, this will have different surface tension. Another dependent variable is the amount increased in the capillaries due to the different surface tension of the substances.

Controlled variable: Using the same beaker, the same ruler, the same amount of ml and the capillaries having the same size are the variables that we control and never changes in the experiment.