Bohr’s Model

Bohr’s Model of the atom is described in Serway pp. 116-130 and Tipler pp.170-177. This model is applicable to any atom or ion having a single electron orbiting a positive nucleus. Examples of these hydrogen-like atoms would be the neutral hydrogen atom, the singly ionized helium atom, the doubly ionized lithium atom, etc.

In order to obtain extremely accurate predictions of the spectra of single electron atoms, it is necessary to employ a reduced mass correction factor. This correction takes into consideration the fact that the electron does not orbit the nucleus but rather the center of mass of the electron-nucleus system. But for most single electron atoms the correction is small and can be neglected to a first approximation.

In addition to proposing his model of the atom, Bohr also proposed his correspondence principle, which asserted that quantum physics must revert to classical physics in the classical limit. We have mentioned the correspondence principle earlier in this course because it not only applies to the physics of atoms but also to every other aspect of modern physics.

Reduced Mass – Using the reduced mass of a two-body system corrects for the motion about the center of mass.
Bohr’s Correspondence Principle – This principle asserts that quantum physics must reduce to classical physics in the classical limit.

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