Bohr Hydrogen Atom

This simulation shows the Bohr model of the hydrogen atom, in which the electron can only occupy certain energy levels. Students choose the level to jump to, turn random jumps on or off, set how often they happen and trigger a jump at any time. Each jump sends out or takes in a photon drawn in its true colour, with readouts for the transition, wavelength, photon energy and spectral series. It is useful for explaining atomic emission spectra, the Balmer and Lyman series and why elements give line spectra.

• Set Jump to level n to 2 and press Random jump now to see which transitions end on n = 2.
• Compare the Photon wavelength for a jump from n = 3 to 2 with one from n = 6 to 2.
• Find a jump that ends on n = 1 and check that the Series readout says Lyman, in the ultraviolet.
• Turn off Random jumps to hold the electron on one level, then step through levels one at a time.
• Change Jump every to 6 s so the class has time to predict each photon energy.

1. 1Explain that electrons in hydrogen occupy fixed energy levels.
2. 2Relate the energy of an emitted photon to the gap between two levels.
3. 3Distinguish the visible Balmer series from the ultraviolet Lyman series.
4. 4Use E = -13.6 eV / n squared to calculate level energies.

Questions teachers ask