Sam blew up a balloon and rubbed it on his head. Then he stuck the balloon on the wall. This was all the result of electrostatics or the transfer of charge. The appearance of negative charge on a balloon is the result of its gaining electrons. And these electrons must come from somewhere; in this case, from Sam's hair. Electrons are transferred in any charging process. In the case of charging by friction, they are transferred between the two objects being rubbed together. Prior to the charging, both objects are electrically neutral and the situation obeys the law of conservation of charge. How does the law of conservation of charge explain Sam and his balloon?
A) Friction creates a charge that collected on the balloon.
B) The balloon gained electrons; Sam's hair gained protons.
C) If the balloon acquires charge, Sam's hair loses charge.
D) The net charge before is zero; the net charge after is negative.
