Figure 5. Copper electrodes before the experiment (top) and after the experiment (bottom)

From

Electrolysis of Water in School Experiments – Simple and Safe Model Experiment for Hydrogen Production Using Everyday Materials for Teaching Purposes

Dominique Rosenberg, Tom Severin Gabriel, Maike Busker, Sven Gehbardt

World Journal of Chemical Education. 2025, 13(4), 91-97 doi:10.12691/wjce-13-4-1