Need help in electric field problem

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Part A
Suppose all the electrons in a quantity of carbon atoms with a mass of 25.0 g were located at the North Pole of the Earth and all the protons at the South Pole. What would be the total force of attraction exerted on each group of charges by the other? The atomic number of carbon is 6, and the atomic mass of carbon is 12.0 g/mol.

Use 8.85×10−12 C^2/N*m^2 for the permittivity of free space, 1.60×10−19 C for the magnitude of the charge on an electron, 6.02×1023 mol^-1 for Avagadro's number, and 6.38×106 m for radius of the earth.

Part B
What would be the magnitude of the force exerted by the charges in part (a) on a third charge that is equal to the charge at the South Pole, and located at a point on the surface of the Earth at the equator?
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Part AThe total number of electrons in 25.0 g of carbon is given by: N_e= (25.0 g * (6.02*10^23 mol^-1))/(12.0 g/mol) = 2.51*10^24 electrons The total force of attraction on each group of charges is given by: F_attraction = (2.51*10^24 * 1.60*10^-19 C^2)/(8.85*10^-12 C^2/N*m^2 * (6.38*10^6 m)^2) = 2.65*10^13 N Part BThe magnitude of the force exerted by the charges on a third charge located at the equator is given by: F_equator = (2.51*10^24 * 1.60*10^-19 C^2)/(8.85*10^-12 C^2/N*m^2 * (4.00*10^7 m)^2) = 5.32*10^11 N