Small Group Activity: Hydrogen emission

Contemporary Challenges 2021
In this activity students work out energy level transitions in hydrogen that lead to visible light.
  • Media
    • 2523/visible-spectrum.png
This activity follows the lecture Quantum waves and spectra
Here is an expression for the energy levels of an electron in a particular situation (an electron bound to a single proton): \begin{align} E_n &= \frac{-13.6\text{ eV}}{n^2} & n&=1,2,3,\cdots \end{align}
  1. Sketch the energy level diagram
  2. Find at least one allowed transition which produces a photon with a visible color
\begin{align} \lambda &= \frac{2\pi\hbar c}{E_{\text{photon}}}\\ &= \frac{1240\text{ eV}\cdot\text{nm}}{E_{\text{photon}}} \end{align}
Visible light spectrum

hydrogen atom photon energy
Learning Outcomes