Answer:
[tex]N=1.375*10^{11}[/tex] electrons
Explanation:
The total charge Q+ at the coin is equal, but with opposite sign, to the charge negative Q- removed of it. Q- is the sum of the charge of the N electrons removed from the coin:
[tex]Q_{-}=N*q_{e}[/tex]
[tex]Q_{-}=-Q_{+}[/tex]
q_{e}=-1.6*10^{-19}C charge of a electron
We solve to find N:
[tex]N=-Q_{+}/q_{e}=-2.2*10^{-8}/(-1.6*10^{-19})=1.375*10^{11}[/tex]
