Two spherical objects are separated by a distance that is 1.80 × 10-3 m. The objects are initially electrically neutral and are very small compared to the distance between them. Each object acquires the same negative charge due to the addition of electrons. As a result, each object experiences an electrostatic force that has a magnitude of 4.55 × 10-21 N. How many electrons did it take to produce the charge on one of the objects?