Answer
$9.0\times 10^{13}~electrons$
Work Step by Step
We can find the total charge in 2 hours:
$Q = (-2.0\times 10^{-9}~C/s)(2~h)(3600~s/h)$
$Q = -1.44\times 10^{-5}~C$
We can find the number of electrons:
$N = \frac{-1.44\times 10^{-5}~C}{-1.6\times 10^{-19}~C} = 9.0\times 10^{13}~electrons$
