An object carries a charge of - 6.1 µC, while another carries a charge of - 2.0 µC. How many electrons must be transferred from the first to the second object so that both objects have the same charge?

Answer: 12,81 * 10^12 electrones

Explanation: In order to equal the charge for this two charged objects we have to pass charge from the object charged with - 6,1 microC to the object charged with - 2.0 microC. We have to transfer - 2.05 microC. Finally the two objects will have 4.05 microC each one.

To do that we have consider the total quantity of charge for the two objects and the we divided by two.

Finally to obtain the number of electrons to be transfered we have to divide the charge to be transfer by the electron charge.

this is 2.05 microC/1.6 * 10^-19 C = 12.81 * 10^12 electrons