How close must two electrons be if the electric force between them is equal to the weight of either at the earth's surface?

Answer 1

Set m g = k e^2/R and solve for R.
m = electron mass = 9.11*10^-31 kg
g = 9.8 m/s^2
e = 1.60*10^-19 C = electron charge
k = Coulomb constant = 8.99*10^9 N-m/C^2
The answer (R) will be in meters

Answer 2

5.08m