الكيمياء اللاعضوية المرحلة الاولى التدريس باللغة الانجليزية
المواضيع الدراسية خلال فصل الخريف
Dr. Mohammed Hashim Matloob
Atomic number, mass number and isotopes
An overview of quantum theory
Orbitals of the hydrogen atom and quantum
The multi-electron atom, the aufbau principle
and electronic configurations
The periodic table
Ionization energies and electron affinities
Valence bond theory
Fundamentals of molecular orbital theory
The octet rule
MO theory: heteronuclear diatomic molecules
Molecular shape and the VSEPR model
المحلضرة الاولى المقدمة
An atom is the smallest unit quantity of an element that is capable of existence, either alone or in chemical combination with other atoms of the same or another element. The fundamental particles of which atoms are composed are the proton, electron and neutron.
Table 1.1 Properties of the proton, electron and neutron.
Successes in early quantum theory
The development of quantum theory took place in two stages. In the older theories (1900–1925), the electron was treated as a particle, and the achievements of greatest significance to inorganic chemistry were the interpretation of atomic spectra and assignment of electronic configurations.
In more recent models, the electron is treated as a wave (hence the name wave mechanics) and the main successes in chemistry are the elucidation of the basis of stereochemistry and methods for calculating the properties of molecules (exact only for species involving light atoms).
Since all the results obtained by using the older quantum theory may also be obtained from wave mechanics, it may seem unnecessary to refer to the former; indeed, sophisticated treatments of theoretical chemistry seldom do. However, most chemists often find it easier and more convenient to considerthe electron as a particle rather than a wave.
Some important successes of classical quantum theory
Historical discussions of the developments of quantum theory are dealt with adequately elsewhere, and so we
focus only on some key points of classical quantum theory (in which the electron is considered to be a particle). At low temperatures, the radiation emitted by a hot bodyis mainly of low energy and occurs in the infrared, but as the temperature increases, the radiation becomes successively dull red, bright red and white. Attempts to account for this observation failed until, in 1901, Planck suggested thatenergy could be absorbed or emitted only in quanta of magnitude ΔE related to the frequency of the radiation, ν. The proportionality constant is h, the Planck constant (h = 6.626 x 10-34 J s).