A negatively charged balloon has 3.1 μC of
charge.
How many excess electrons are on this bal-
loon?
Answer in units of electrons.
1 answer
each electron has a magnitude of charge 1.602*10^-19. So, divide the excess charge by the single electron charge to get a number of electrons. (3.1*10^-6 Coul)/(1.602*10^-19 Coul/e) = 1.9 *10^13 excess electrons.