Now reset the balloon. Again, collect the blue negative charges from the sweater, by rubbing the balloon on the sweater. Even bring the balloon close to the wall again. What do you notice about the movement of the negative charges in comparison to the positive charges? Explain why.
When resetting the balloon and rubbing it on the sweater to collect blue negative charges, the movement of these negative charges is the same as before. They move towards the positive charges present on the wall.
This happens because opposite charges attract each other. In this case, the negatively charged balloon is attracted to the positively charged wall. The positive charges on the wall are immobile, so they cannot move towards the balloon. Instead, the negative charges on the balloon move towards the positive charges on the wall due to the attractive force between opposite charges.