Principle 

Water conducts electricity since it contains ions acting as charge carriers. However, since tap water is not sufficiently conductive in order to make the lamp in this set-up light up, bath salts are used. They increase the number of ions and, thereby, the conductivity of the water. The use of bath salts can be justified by explaining that it is used to simulate a bath. Later on, it will be discussed that "in real life" with 230 V from a wall socket (compared to 4.5 V of the battery), the conductivity of unsalted water would be sufficient and that serious accidents will occur if a hair dryer or radio drops into the bath by accident.

Benefits

•  The experiment is part of a comprehensive solution with a total of 5 demonstration experiments and 15 student experiments around the topic of water.
• The matching set includes all of the accessories that are required for performing the experiment.