Answer
$1.25 \times 10^{19}$
Work Step by Step
The rate of charge flow is known as current, and we can represent it as $i$. For a given charge $q$ and a time $t$, we have $ q = it$.
We also know that charge is quantized, which means that for integral values of $n$, $q =ne$ where $e$ is the charge of an electron.
Accordingly, we have . . .
$ ne = it \implies n = \frac{it}{e} = \frac{(20000)(100\times10^{-6})}{1.6\times 10^{-19}} = 1.25 \times 10^{19}$
