Pauli Exclusion Principle - · PDF file 2016. 3. 8. · Pauli Exclusion Principle Fundamental principle -- Pauli Exclusion Principle Any fundamental particles with Odd/2 spin can not

Microsoft PowerPoint - Lec15.pptxPHYS 342 Modern Physics Atom V: Many –Electron Atoms
Today Contents: a) Pauli Exclusion Principle b) Electron States in ManyElectron Atoms c) Outer Electron and Optical Transition
Pauli Exclusion Principle
Fundamental principle -- Pauli Exclusion Principle Any fundamental particles with Odd/2 spin can not have the same set of quantum numbers in a quantum system.
No two electrons can have the same set of quantum number (n, l , ml, s , ms ) in a single atom.
Occupation Number of Atomic States
( n, l , ml, s , ms ) energy  Level
orbital AM
spin AM
Electron ConfigurationsShow the electrons in orbitals –Box used to represent orbital –Half arrow used to represent e with  opposite spins
Electrons are placed in orbitals of lowest energy first
Electron Configuration
2p
The correct way: Use sum of n+l to determine which orbital fills first.
Rule#1.
Naive thinking: The energy increases from the smaller n to the larger n. For the same n, from the smaller p to the larger p.
It is wrong!
3s 3p
2pLi C
Rule#2: The electron prefers to occupy different ml states first.
Minor Variation: Half filling and Full Filling
Rule#3
1s 2s 2p 3s 3p
(1 0 0) (2 0 0) (2 1 -1), (2 1 0), (2 1 1) ? ? ? ?
(n, l, ml)
ICP 31
#
1 ? ? ? ? ?
The Periodic Table Five basic category: Inert gas (Full p-shell), p-subshell,
S-subshell, Transition Metals (d-shell filled first than p-shell)
Lanthanides and Actinides (f-shell filled first than d-shell) https://www.youtube.com/watch?v=xqoQfN9DgNs
3/8/2016
5
ICP 32
If the effective nuclear charge for lithium n=2 orbit electron is 1.26e, then what is the ionization energy for lithium atom n=2 electron. (use eV in your answer)
Periodic Physical Properties Periodic Physical Properties
3/8/2016
6
2 / 2 /
2 /
Optical Transition The transition of outer electron between the ground and excited states make the atom emits/absorbed light.
Li: 1 2 Na: 1 2 2 3
Spectrum- tool for atomic world
https://www.youtube.com/watch?v=RFFfYlq3oEo Transient Absorption Spectroscopy
https://www.youtube.com/watch?v=pxC6F7bK8CU spectrophotometer
EXAM 2 (Monday March 21rd)
a) 3 steps to solve Schrodinger Equation   b) 6 special cases for Schrodinger Equation (free particles.  Infinite potential well, finite potential well,  potential barrier,  potential step, simple harmonic oscillator) c) 2 models for hydrogen atom: Rutherford Model and Bohr  Model  d) 3 probability of for hydrogen atom wave function: angular  probability , radial probability, probability density   e) 3 angular momentum and magnetic dipole: orbital, spin and  total  f) 7 Quantum Numbers g) 3 rules to fill the electron states h) 1 method: how to add angular momentum
HW8
ICP 31-32