The electrostatic force exerted by a point charge on a test charge at a distance r depends on the charge of both charges, as well as the distance between the two.
Visualize the electrostatic force that two charges exert on each other. Observe how changing the sign and magnitude of the charges and the distance between them affects the electrostatic force.
The strength of the electric force between two charges is inversely proportional to the square of the distance between the charges.
Strength of electric force
The electric force is about 37 orders of magnitude stronger than the gravitational fore.