Use the model to connect atomic number with electrons and shell arrangement. The Bohr model is useful for introductory ideas about quantized energy levels, while modern atoms require quantum mechanics.
Bohr proposed allowed energy levels for electrons. A transition between levels can involve absorption or emission of a photon.
Photon energy is related to frequency by E = hf. Discrete energy differences help explain line spectra.
For a neutral atom, atomic number equals the number of electrons. The shell display is a simplified educational representation.
The Bohr picture is not a literal map of electron motion for multi-electron atoms; orbitals and quantum effects are needed for a fuller description.
Choose an element, inspect its atomic number and shell data, and compare the arrangement across elements.