Two electrons are separated by 2.00 nm. What is the magnitude of the electric force each electron exerts on the other?

An electric force is given by F = (kqQ)/(r^2) where k is the constant 9x10^9, q and Q are the charges, and r is the distance between the charges.

Given that the charge of an electron is -1.6 x 10^-19 C, we can write the force equal to

((9x10^9)(-1.6x10^-19)^2)/(2x10^-9)

=> 1.152 x 10^-19 N

Note that the force is repulsive since the electrons are both negatively charged (the same sign).