Four identical metal spheres have charges of qA = -8.0 µC, qB=-2.0 µC, qC=+5.0 µC, and qD=+12.0 µC.
(a) Two of the spheres are brought together so they touch, and then they are separated. Which spheres are they, if the final charge on each one is +5.0 µC?
(b) In a similar manner, which three spheres are brought together and then separated, if the final charge on each of the three is +3.0 µC?
(c) The final charge on each of the three separated spheres in part (b) is +3.0 µC. How many electrons would have to be added to one of these spheres to make it electrically neutral?