In hydrogen like system the ratio of coulombian force and gravitational force between an electron and a proton is in the order of [2024]
(1)
Fe=kQ1Q2r2=9×109×1.6×10-19×1.6×10-19r2
Fg=Gm1m2r2=6.67×10-11×9.1×10-31×1.6×10-27r2
FeFg≅0.23×1040≅2.3×1039