Answer:
[tex]1.44\cdot 10^{-20} J[/tex]
Explanation:
The difference in electric potential between the inside and the outside of the cell is
[tex]\Delta V = 0.09 V[/tex]
The work done by the electric force to bring the ion from outside to inside is
[tex]W=q\Delta V[/tex]
where
q is the charge of the ion
A sodium ion, [tex]Na^+[/tex], has given off an electron: so its electric charge is
[tex]q=+e=+1.6\cdot 10^{-19} C[/tex]
Therefore, the work done is:
[tex]Q=(1.6\cdot 10^{-19})(0.09)=1.44\cdot 10^{-20} J[/tex]