Question

at what distance the two electrons should we keep so that the force between them becomes equal to weight of one electron

Answer 1

Electrostatic force between two charges is given by F=(q1)(q2)/(4πεο r^2). εο is the permittivity of free space with the value of 8.85*10^-12. q is the charge of an electron i.e. 1.60*10^-19 C

Here F given is = Weight of a electron = 9.1 * 10^-31 kg

We have to just put the values in given formula and you will get the answer. Hope it helps you :)