The electrical force between two charges q1 and q2 is given by
[tex]F=k \frac{q_1 q_2}{r^2} [/tex]
where
[tex]k=8.99 \cdot 10^9 Nm^2C^{-2}[/tex] is the Coulomb's constant
q1 and q2 are the two charges
r is the separation between the two charges
If you know the value of the two charges, q1 and q2, and their separation r, you can simply put these numbers into the equation, to find the intensity of the electrical force.
