(BQ) Part 2 book "Elements of physical chemistry" has contents: Quantum theory, quantum chemistry - atomic structure, quantum chemistry - The chemical bond, materials - macromolecules and aggregates, solid surfaces,.and other contents. | Chapter 12 Quantum theory Three crucial experiments Atomic and molecular spectra The photoelectric effect Electron diffraction The dynamics of microscopic systems The Schrödinger equation The Born interpretation The uncertainty principle Applications of quantum mechanics Translational motion (a) Motion in one dimension (b) Tunnelling (c) Motion in two dimensions Rotational motion (a) Rotation in two dimensions (b) Rotation in three dimensions Vibrational motion CHECKLIST OF KEY IDEAS TABLE OF KEY EQUATIONS QUESTIONS AND EXERCISES The phenomena of chemistry cannot be understood thoroughly without a firm understanding of the principal concepts of quantum mechanics, the most fundamental description of matter that we currently possess. The same is true of virtually all the spectroscopic techniques that are now so central to investigations of composition and structure. Present-day techniques for studying chemical reactions have progressed to the point where the information is so detailed that quantum mechanics has to be used in its interpretation. And, of course, the very currency of chemistry—the electronic structures of atoms and molecules—cannot be discussed without making use of quantum-mechanical concepts. The role—indeed, the existence—of quantum mechanics was appreciated only during the twentieth century. Until then it was thought that the motion of atomic and subatomic particles could be expressed in terms of the laws of classical mechanics introduced in the seventeenth century by Isaac Newton (see Appendix 3), as these laws were very successful at explaining the motion of planets and everyday objects such as pendulums and projectiles. However, towards the end of the nineteenth century, experimental evidence accumulated showing that classical mechanics failed when it was applied to very small particles, such as individual atoms, nuclei, and electrons, and when the transfers of energy were very small. It took until .
