Atomic Emission Spectrum Simulator

This simulator visualizes the quantum-mechanical process behind every atomic emission line: an electron bound to a nucleus can only sit at discrete, quantized energy shells, and every jump between shells emits or absorbs a photon at one exact energy. Choose a target shell and fire an absorption photon into the atom — the electron jumps up instantly, then cascades back toward the ground state one or more levels at a time, releasing a real, physically-computed photon at each step. Each photon's energy, wavelength and visible color follow the same Rydberg-style formula used for real hydrogen spectral lines, and every emission adds a colored tick to the spectrum strip so you can watch a genuine line spectrum build up transition by transition.