Atoms And Nuclei

The ratio of Coulomb's electrostatic force to the gravitational force between an electron and a proton separated by some distance is 2.4 \(\times\) 10³⁹. The ratio of the proportionality constant, \(K = {1 \over {4\pi {\varepsilon _0}}}\) to the gravitational constant G is nearly (Given that the charge of the proton and electron each = 1.6 \(\times\) 10^\(-\)19 C, the mass of the electron = 9.11 \(\times\) 10^\(-\)31 kg, the mass of the proton = 1.67 \(\times\) 10^\(-\)27 kg) :