🪜 Energy levels — a 3D ladder, and the photon from every jump

The levels of a one-electron atom bunch up toward zero. Pick a jump and the electron drops from one rung to another, releasing a photon whose energy is exactly the gap between them.

Walkthrough 1 / 4

Step 1 — the energy-level discs, stacked by their real energies and crowding toward the top.

Start level n_i 3

End level n_f 2

Nuclear charge Z 1

E_i = -1.51 eV · E_f = -3.40 eV
ΔE = 1.89 eV · λ = 656 nm

levels crowd toward E = 0 (ionisation)
Z² deepens every level together

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