Triboelectrics.... Help please. this problem is a worked example in my textbook.. but it looks like they have just pulled numbers from thin air. I really dont understand how they got these answers.. can anyone explain? A perspex rod is rubbed with a piece of silk. it acquires a charge of 0.02uC a) How many electrons are transferred? b) is this charge is now transderred to an electroscope with charge +0.01uC what will be the net state of the electroscope? Book's Solution: 0.02 x 10^-6 x 6.25 x 10^18 electrons -or- a) 1.25x10^-11 electrons transferred. b) total charge on the electroscope after transfer: 0.02uC + 0.01uC = 0.03uC (+) the electroscope leaf deflection will increase and the net charge on the electroscope is now +0.03uC = 1.87x10^11 electrons depleted I really dont understand, can anyone help?