Question

Compare the magnitude of the electrostatic and gravitational force between an electron and a proton at a distance r apart in hydrogen atom. (Given : me = 9.11 × 10⁻³¹ kg ; mP = 1.67 × 10⁻²⁷ kg ; G = 6.67 × 10⁻¹¹ Nm² kg⁻²; e = 1.6 × 10⁻¹⁹ C)

Answer 1

The gravitational attraction between electron and proton is

Let r be the average distance between electron and proton in hydrogen atom. The electrostatic force between the two charges  

This shows that the electrostatic force is 2.27 × 10³⁹ times stronger than gravitational force.