The diagrams below illustrate an experiment. The bulb on the left is not lit. The bulb on
the right is lit. Both bulbs are in perfect working condition. Answer the questions that
follow. H20 is water. NaCl is sodium chloride, which is salt.
H20 H20 + Electrode
1. What observations can you make which are the same for both set-ups?
2. What is different about the diagram on the right?
3. What problem is being investigated here?
4. State the problem in the form of a hypothesis.
5. Is this hypothesis testable?
6. What is the manipulated variable?
7. What is the responding variable?
8. What would be some of the control variables? (Name at least two.)