Question

The charge of the part is 5.0 nC. How many electrons is there in it?

Answer 1

We can find the number of the electrons from the formula:

$$q=Ne,$$

here, $q=5\cdot 10^{-9}\ C$ is the charge of the part, $N$ is the number of the electrons, $e=1.6\cdot 10^{-19}\ C$ is the charge of the electron.

Then, we get:

$$N=\dfrac{q}{e}=\dfrac{5\cdot 10^{-9}\ C}{1.6\cdot 10^{-19}\ C}=3.12\cdot 10^{10}\ electrons.$$

Answer:

$N=3.12\cdot 10^{10}\ electrons.$