Two neutral metal spheres on insulating stands are placed in contact as shown in the figure. A negatively charged rod (how might we create such a thing?) is then brought directly over the top of the left sphere without touching either sphere. While the rod is held still, the right sphere is moved so that the spheres no longer touch. Then the charged rod is withdrawn. After the rod is withdrawn, what is the charge state of each sphere (neutral, positive, or negative)? Use words and pictures to explain your answers.