quantum mechanical mode.doc

The quantum mechanical model is based on mathematics. Although it is more difficult to understand than the Bohr model, it can be used to explain observations made on complex atoms. The quantum mechanical model is based on quantum theory, which says matter also has properties associated with waves. According to quantum theory, it’s impossible to know the exact position and momentum of an electron at the same time. This is known as the Uncertainty Principle. The quantum mechanical model of the atom uses complex shapes of orbitals(sometimes called electron clouds), volumes of space in which there is likelyto be an electron. So, this model is based on probability rather than certainty. Four numbers, called quantum numbers, were introduced to describe the characteristics of electrons and their orbitals:  Principal quantum number: n  Angular momentum quantum number: l

 Magnetic quantum number:   Spin quantum number: 

A powerful model of the atom was developed by Erwin Schrodinger in 1926. Schrodinger combined the equations for the behavior of waves with the de Broglie equation to generate a mathematical model for the distribution of electrons in an atom. The advantage of this model is that it consists of mathematical equations known as wave functions that satisfy the requirements placed on the behavior of electrons. The disadvantage is that it is difficult to imagine a physical model of electrons as waves. The three coordinates that come from Schrodinger's wave equations are the principal (n), angular (l), and magnetic (m) quantum numbers. These quantum numbers describe the size, shape, and orientation in space of the orbitals on an atom.

Werner Heisenberg-He devised a method to formulate quantum mechanics in terms of matrices, for which he was awarded the 1932 Nobel Prize for Physics. -Heisenberg formulated the quantum theory of ferromagnetism, the neutronproton model of the nucleus, the S-matrix theory in particle Louis de Broglie scattering, and various other -best known his research in significantfor breakthroughs on quantum quantum theory and for field theory and highpredicting the wavenature energy particle physics are of electrons. washim awarded the associatedHe with 1929 Nobel Prize for Physics. -He developed new theories in -De Broglie’s idea of an electron with quantum mechanics about the the properties of a wave offered an behavior of electrons which explanation of the restricted motion. agreed with the results of A wave confined within boundaries previous experiments. imposed by the nuclear charge would Heisenberg mostand, famous be restricted in is shape thus,for in his "uncertainty principle", motion, because any wave shape which explains thethe impossibility that did not fit within atomic of knowing exactly where boundaries would interfere with itself something is and fast when it is and be canceled out. how In 1923, de moving. Broglie put forward this idea, there was no experimental evidence whatsoever that the electron, the corpuscular properties of which were well established by experiment, might under some conditions behave as if it were radiant energy.