With rising oil prices and increasing concerns over global warming, the pressure is on for engineers to develop alternative sources of energy. Among the new technologies being developed are hydrogen fuel cells, which young scientists investigate in this series of four experiments. Using a fuel cell car kit, middle schoolers learn about the process of electrolysis as they measure the oxygen and hydrogen produced by decomposing water. Note that the experiments are somewhat complicated, so consider walking students through the procedures step by step to ensure the safe and successful completion of the lesson.