Question

How far does the electron of a hydrogen atom have to be moved from the nucleus for the force of attraction in the electron to equal the weight at the earth surface. Mass of earth, proton and nucleus are given. Also given are charge of an electron, proton. Mass of neutron is given as 0

Answer 1

$$r=\sqrt\frac{kq_1q_2}{m_\text{H}g}=0.1186\text{ m}.$$