ACS Chemistry Practice Exam 2026 – The All-in-One Guide to Exam Success!

The Bohr model of the atom has a significant limitation in that it permits only specific orbits for the electron in hydrogen. This model, introduced by Niels Bohr in 1913, laid a foundation for understanding atomic structure by proposing that electrons revolve around the nucleus in fixed circular orbits, each corresponding to a specific energy level. While this model successfully explained the spectral lines observed in hydrogen, it is limited to hydrogen-like atoms due to its strict quantization of electron orbits.

In contrast, the behavior of electrons in larger atoms becomes more complex. The Bohr model does not account for electron-electron repulsion, which becomes increasingly significant as additional electrons are introduced in larger atoms, nor does it incorporate the principles of wave-particle duality and quantum mechanics that apply to multi-electron systems. Therefore, while Bohr's model accurately describes hydrogen, it struggles to explain the spectra and behavior of more complex atoms, which leads to its limited application in modern chemistry.