Two charges, q1 and q2, are separated by a certain distance r. if the magnitudes of the charges are halved and their separation is halved, then what happens to the electrical force between these two charges?

The electrical force between these two charges remains the same. In coulomb’s law, it states that the magnitude of two charges (product of two charges) is inversely proportional to the square of the distance. Since both the magnitude and the distance are halved, therefore, the change in both quantities will have no effect in the value of electrical force.