## Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)

$N = 8.4\times 10^{21}$
We can find the total charge delivered in 30 minutes: $Q = (-0.75~C/s)(30~min)(60~s/min) = -1350~C$ We can find the number of electrons: $N = \frac{-1350~C}{-1.6\times 10^{-19}~C} = 8.4\times 10^{21}$