Answer
Electrons move from the fur to the first rod so it becomes negatively charged. The electrons in the second rod are pushed away which exposes positive charges in the second rod. These positive charges are attracted to the negatively charged rod. When the two rods come in contact, some electrons move from the first rod onto the second rod. Since both rods are then negatively charged, they repel each other.
Work Step by Step
When the first plastic rod is rubbed with the fur, electrons move from the fur to the rod so the rod becomes negatively charged. The electrons in the second rod are pushed away which exposes positive charges in the second rod. These positive charges are attracted to the negatively charged rod, so the second rod swings toward the first rod. When the two rods come in contact, some electrons move from the first rod onto the second rod. Since both rods are then negatively charged, they repel each other.