Four ions (Na+, Cl-, Na+, and Cl-) in a row are each separated from their nearest neighbor by 3.0x10^-10 m. The charge of a sodium ion is +e and that of a chlorine ion is -e.
Part A:
Determine the electric force exerted on the chlorine ion at the right end of the row due to the other three ions. (+x to the right)
Express your answer with the appropriate units.