The force exerted by a proton on an electron, and vice versa, is the same in magnitude but opposite in direction. This is due to Newton's Third Law of Motion, which states that for every action, there is an equal and opposite reaction.

Here's why:

* Electromagnetic force: The force between the proton and electron is the electromagnetic force. This force is attractive because protons have a positive charge and electrons have a negative charge.

* Coulomb's Law: The magnitude of the electrostatic force between two charged particles is determined by Coulomb's Law:

* F = k * (q1 * q2) / r²

* Where:

* F is the force

* k is Coulomb's constant

* q1 and q2 are the magnitudes of the charges

* r is the distance between the charges

Since the charges of the proton and electron have the same magnitude (though opposite signs), and the distance is the same, the force they exert on each other will be equal in magnitude.

In summary: While the proton and electron experience oppositely directed forces due to their opposite charges, the magnitude of the force they exert on each other is the same.