Answer:
[tex]-1.6\cdot 10^{-18}C[/tex]
Explanation:
The charge of a single electron is:
[tex]q=-1.6\cdot 10^{-19}C[/tex]
If the oil droplet has N electrons, the total charge of the droplet will be
[tex]Q=Nq[/tex]
In this case, we have
N = 10
Therefore, the total charge on the droplet is
[tex]Q=(10)(-1.6\cdot 10^{-19} C)=-1.6\cdot 10^{-18}C[/tex]