In the Rutherford Model of the Hydrogen Atom, a Proton $\pi$

Multiple Choice

In the Rutherford model of the hydrogen atom, a proton (mass M, charge Q) is the nucleus and an electron (mass m, charge q) moves around the proton in a circle of radius r.Let k denote the Coulomb force constant (1/4 $\pi$ ) and G the universal gravitational constant.The ratio of the electrostatic force to the gravitational force between electron and proton is:

A) kQq/GMmr²
B) GQq/kMm
C) kMm/GQq
D) GMm/kQq
E) kQq/GMm