Final answer:
1. The electric force between two charged particles quadruples if both charges are doubled, as Coulomb's law dictates the force is directly proportional to the product of the charges.
Step-by-step explanation:
To understand what happens to the electric force between two charged particles when their charges change, we rely on Coulomb's law. This law states that the force is directly proportional to the product of the charges and inversely proportional to the square of the distance between the particles.
When the charge of one particle is doubled (assuming the other charge is unchanged), the electric force also doubles (2F). However, if the charge of both particles is doubled, the electric force quadruples (4F). This is because the force is proportional to the product of the two charges. The correct answer is that the force quadruples if both charges are doubled.
Therefore, the correct response to the question is option 2: The electric force between the particles quadruples in both cases. If only one charge is doubled, the force doubles; if both are doubled, the force quadruples.