What two things will affect size of the electric force between two objects?

The two things that affect the size of the electric force between two objects are "amount of charge on each object and distance between the charges".

Explanation:

The magnitude and sign of the electric force are estimated by the electric charge in "Coulombs Law" inspite of mass an object which is favorable in gravitational force. Therefore charge is the property of electromagnetism which influences the charged objects' motion.

More the charge on object more will be the electric force, as bigger charge cloud have more force than smaller. The electric force is inversely proportional to the square of the distance between the two charges. This showcase weaker attraction or repulsion as the distance increases between the two charges.