The problem statement, all variables and given/known data A negatively charge balloon has 2.4 μC of charge. How many excess electrons are on this balloon? The elemental charge is 1.6e-19 C. Answer in units of electrons. The attempt at a solution I keep getting 1.5e13 electrons but the system is telling me it's wrong. I put it in many different forms and it still won't take it. (ex: 15000000000000) Is there something that I'm missing here?