A science activity in the English class of 6th of Primary. We are learning about electricity and how electrons can move from one object to another.
In this experiment we can see how the ruler is negatively charged, so it attracts positively charged protons in the pieces of paper. If you want to try it you have to take a plastic ruler and a piece of woollen cloth. They are electrically neutral, but if you rub the ruler with the cloth, some of the electrons in the cloth will pass into the ruler. In the end, the ruler will have more electrons than protons, so it will be negatively charged. The cloth will have more protons than electrons, so it will be positively charged.
In this other experiment we can see how electricity charged objects will attract or repel each other, depending on their charges. There is a force of attraction between objects that have got opposite electric charges. There is a force of repulsion between objects that have got identical electric charges.