Two identical metal spheres a and b are connected by a plastic rod. both are initially neutral. 1.0×1012 electrons are added to sphere a, then the connecting rod is removed. part a afterward, what is the charge of a? express your answer using two

The plastic rod is made of insulator (plastic), so it does not allow charges moving from one sphere to another. This means that all the electrons given to sphere A will remain on sphere A.

The number of electrons initially given to sphere A is , and since the charge of 1 electron is , the net charge left on sphere A after the removal of the rod will be