Sandy rubs a rubber rod with a piece of animal fur. The total charge of the system before rubbing is zero. The system is made up of the rubber rod and the fur. Initially, the charge on the rod is zero and it is electrically neutral. The same is true for the fur. When Sandy rubs the rubber rod with the fur, the rubber rod acquires negative (-) charges. How does the system change, overall, based on the law of conservation of charge?