Simulation of Energy levels to demonstrate that:
“The electron arrangements may change with the absorption of electromagnetic radiation (move further from the nucleus; a higher energy level) or by the emission of electromagnetic radiation (move closer to the nucleus; a lower energy level).”
What the simulation does
The simulation models the hydrogen atom using the Bohr model (E_n = −13.6/n² eV). It has two interactive modes:
In Absorption mode, the electron starts at n = 1 (ground state) and the user clicks a higher shell. A photon travels inward, the electron absorbs it and jumps up. The shell labels show the exact energy levels (e.g. −3.40 eV at n = 2), and the stats panel displays the photon’s wavelength and its region of the spectrum — Lyman series transitions all produce UV, as expected.
In Emission mode, the electron starts at n = 5 and the user clicks a lower shell. The electron drops, emitting a photon outward. Balmer series transitions (dropping to n = 2) produce visible light — red at 656 nm, blue at 486 nm, violet at 434 nm — which the simulation shows with the correct spectral colour.
Suggested classroom activity — “Predict, Click, Record”
This works well for GCSE or A-level students studying atomic structure and line spectra.
Give students a simple worksheet before they open the simulation. Ask them to use the formula E = hc/λ and the energy level values shown on screen to predict the wavelength and colour of three specific transitions — for example n=3→1, n=4→2, and n=5→3. They write down their predictions, then use the simulation to check, recording whether the photon was in the UV, visible, or infrared region and why.
A follow-up discussion question works well here: “Why do transitions to n=1 always produce UV light, while transitions to n=2 can produce visible colours?” This pushes students to reason about the size of the energy gap rather than just reading off values.
For a SEND-friendly adaptation, students can work in pairs — one operating the simulation, one recording — with a pre-filled table that already labels the series names (Lyman, Balmer, Paschen) so the cognitive load focuses on the concept rather than data management.