Senku and his comrades decide to upgrade their tank by making paper. They gather lots of weed and boil it with sodium hydroxide to turn it into goo. They then press and dry it in the sun to solidify paper.
Beakman uses ping pong balls to simulate electrons. He rolls them down a pipe that gets narrower so they pile up (resistance). In a light bulb, the resistance causes the coil to heat up and make light.
Beakman and Liza explain how static electricity works. They use plenty of real-world examples and humorous graphics in their explanation. They include atoms and electrons in their explanation.