---
title: "In a classical model of the hydrogen atom, an electron of charge \\(-e\\) and mass \\(m\\) orbits a stationary proton of charge \\(+e\\) in a circular path of radius \\(r_0\\). The electron is then transferred to a stable circular orbit of radius \\(2r_0\\). What is the minimum work that an external agent must perform to remove the electron from this outer orbit to infinity and bring it to rest?"
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url: "https://nerd-notes.com/ubq/118052/"
date_modified: "2026-08-04T08:04:54+00:00"
---

# In a classical model of the hydrogen atom, an electron of charge \(-e\) and mass \(m\) orbits a stationary proton of charge \(+e\) in a circular path of radius \(r_0\). The electron is then transferred to a stable circular orbit of radius \(2r_0\). What is the minimum work that an external agent must perform to remove the electron from this outer orbit to infinity and bring it to rest?

In a classical model of the hydrogen atom, an electron of charge \(-e\) and mass \(m\) orbits a stationary proton of charge \(+e\) in a circular path of radius \(r_0\). The electron is then transferred to a stable circular orbit of radius \(2r_0\). What is the minimum work that an external agent must perform to remove the electron from this outer orbit to infinity and bring it to rest?

- **A.** \(\dfrac{e^2}{32\pi\varepsilon_0 r_0}\)
- **B.** \(\dfrac{e^2}{8\pi\varepsilon_0 r_0}\)
- **C.** \(\dfrac{3e^2}{16\pi\varepsilon_0 r_0}\)
- **D.** \(\dfrac{e^2}{16\pi\varepsilon_0 r_0}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/118052/*