Introduction to Quantum Mechanics

In Chapter 2 we saw that classical mechanics was incapable of explaining the optical spectra emitted by atoms, or even the existence of atoms. Bohr developed a model for the atom of hydrogen by assuming the quantization of the angular momentum, which was an introduction to wave or quantum mechanics. Quantum mechanics is a more precise approach to describe nearly all physical phenomena which reduces to classical mechanics in the limit where the masses and energies of the particles are large or macroscopic.

In this section, we will illustrate the success of quantum mechanics through the historically important examples of blackbody radiation, waveparticle duality, the photoelectric effect, and the Davisson and Germer experiment.