Abstract

Understanding of the nature of the atoms, molecules and more complex system properties is directly related to the distribution and behavior of their microscopic particles. Somel experimental evidence suggests that the structure of atoms and molecules could not be explained by principles based on classical mechanics. Experiments, such as black body radiation, heat capacity and atomic and molecular spectra, suggested that the processes of absorption or emission of energy could only be explained by assuming that the energy involved in these processes would be quantized and not continuous, as assumed by classical mechanics. The new mechanics designed to reconcile the issues observed with the quantization hypothesis of certain microscopic properties were called Quantum Mechanics.
Two versions of this new mechanics have been formulated by the physicists Erwin Schrödinger and Werner Heisenberg through different but equivalents mathematical methods, as described in their papers. These theories specify the laws that any microscopic system of particles must obey. There is a relationship with Newton’s theory for the motion of macroscopic systems (principle of correspondence), being Newton’s theory a particular case (at the macroscopic limit) of the Schrödinger equations, as the theory of relativity of Einstein is a generalization that includes the theory of Newton as a special case, at low speeds limit. The Schrödinger’s model is based on some assumptions which are described below.

Keywords
black body radiation, heat capacity, atomic spectra, molecular spectra, quantum mechanics, Schrödinger equation

Authors
Rogério Custodio
André Severo Gomes
Lucimara Ramos Martins
João Carlos de Andrade
Universidade Estadual de Campinas, Instituto de Química

Translated by
João C. de Andrade

Revised by
Carol C. Collins