7. When resetting the balloon and collecting blue negative charges from the sweater, the movement of the negative charges is similar to that of positive charges, meaning they move towards the wall. This is because the wall is a conductor and when charged objects are brought close to it, the charges redistribute themselves to create an electrically neutral state.
8. When rubbing the balloons on the sweater and placing one balloon far away on the right, then bringing the other balloon close to it, the balloons will attract each other. This is because when rubbing the balloons on the sweater, they both acquire a negative charge. Since like charges repel and opposite charges attract, the negative charges on the balloons will attract the positive charges on the other balloon, causing them to move towards each other.