1 / 24

Atomic Physics

Explore the atomic world with Dimitri Mendeleev in Lecture 15, delving into the periodic table of elements, Schroedinger’s Equation, energy shells, and quantum states. Learn about atomic properties, electron configurations, chemical bonding, molecular formation, and atomic spectra. Discover the principles behind electron states, quantum energies, quantum jumps, and the conservation of parity in quantum mechanics. Dive into the fascinating realm of atomic redshifts, laser technology, and applications of stimulated emission of radiation. Gain a deeper understanding of atomic structure and behavior through Mendeleev's insightful lecture.

jaxon
Télécharger la présentation

Atomic Physics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Atomic Physics Micro-world Macro-world Lecture 15 Dimitri Mendeleev

  2. Periodic table of elements Elements in vertical rows have similar chemical properties Inert gases

  3. Schroedinger’s Equation for multi-electron Atoms - - - + - -

  4. Solutions give energy levels that are clustered in “shells” n # of states - - - - 1 2 - - 2 8 - - - 3a 8 + 3b 10 - - - - - - 4a 8 - 4b 10 4c 14 - -

  5. Pauli exclusion principle Wolfgang Pauli Only one electron per quantum state Once a quantum state is occupied additional electrons are excluded

  6. Light elements - +2 +1 - - outermost shell is full 1 electron in outermost shell Helium Hydrogen - - - - - - - +3 +10 - - - - - - Neon Lithium

  7. Periodic table of elements Elements in vertical rows have similar chemical properties 1 e- in outer shell Filled outer shell

  8. Chemical properties depend upon the outermost shell configuration - - - - - - - - - - - +8 - - - - +16 - - - - - - - Oxygen Outermost shells Have 2 vacancies - - Sulfur

  9. Periodic table of elements 2 vacancies in outer shell

  10. Atoms combine to form molecules by filling outer shells +1 Hydrogen - - - Water=H2O - - +8 - - - - - Hydrogen +1 Oxygen

  11. Atoms combine to form molecules by filling outer shells Hydrogen Hydrogen +1 - - +1 - - - Methane=CH4 +6 - - - - - +1 +1 Carbon Hydrogen Hydrogen

  12. Elements with full outer shells don’t form molecules - - - - - - - - - - - - - - +2 - +10 +18 - - - - - - - - - - Helium - - - Neon - - Noble gasses Argon

  13. Periodic table revisited Elements in vertical rows have same outer shell configurations 1 elec in outer shell 2 vacancies in outer shell 4 e- in outer shell Outer shell is full

  14. Quantum theory & Atomic spectra

  15. Spectra are atomic “signatures” Hydrogen Mercury Neon

  16. Decoding atomic spectra Mercury spectrum “quantum jump” photon Ephoton=E2-E1 quantum energies quantum orbits Mercury energy levels

  17. 1924 Otto Laporte Allowed quantum states are either even or odd Laport rule odd Otto Laporte 1902-1971 even even even even odd odd odd even odd OK odd even not allowed even X even odd X odd

  18. Laporte rule is a consequence ofLeft-Right symmetry of Nature Left Right symmetry = “Parity” symmetry Eugene Wigner 1902-1995 Eugene Wigner 1902-1995 1963 Nobel Physics prize “for the discovery and application of fundamental symmetry principles”

  19. P = Parity = L R/R L Field (& rules) of football are parity symmetric Rules of baseball are not parity symmetric

  20. Even & Odd quantum functions Even Function Odd Function LR RL LR RL Does not change Changes sign Parity = +1 Parity = -1

  21. Parity Conservation in QM Left Right symmetry of Nature Conservation of Parity photon has P=-1 even state initially: even state (Peven=+1) finally: odd state+ (Podd=-1) Photon (Pphot=-1) odd state Pinitial=+1 Pfinal=(-1)(-1)=+1 Parity is conserved

  22. Atomic red shifts V=0.25c=75,000km/s l shift = 25% V=0.05c=15,000km/s l shift= 5% V=0.01c=3,000km/s l shift = 1%

  23. Laser – Light Amplification by Stimulated Emission of Radiation – Example: Helium-Neon Laser Cartoon: sealed container I I I Helium-Neon gas mixture mirror “partial” mirror + - Helium-Neon Laser in real life Power source

  24. Laser – Light Amplification by Stimulated Emission of Radiation – “Pump” → Ne* → → “meta-stable” states Ne* → → → Ne* → → Ne* → → → Stimulates emission Ne* → Exactly in phase → → Ne* → Exactly in phase Exactly in phase

More Related