1 / 32

Images of atoms

Explore the various atomic models and delve into the concepts of quantum mechanics. Learn about the movement and behavior of atoms, the formation of molecules, and the probabilistic nature of quantum particles. Discover how these models are essential for understanding and predicting phenomena in science and technology.

afranco
Download Presentation

Images of atoms

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. Images of atoms Dick Hoekzema Ed van den Berg Gert Schooten Centre for Physics Didactics University of Utrecht

  2. Atomic models Kinetic theory of gases • Molecules/atoms move randomly at great speeds • Their number is huge • Their proper volume is negligible • Forces only during (elastisc) collisions

  3. Andere modellen • Liquid, solid state • Volume and mutual attraction no longer negligible • Collisions not elastic • Elektricity: • Particles (can) carry charge • Chemistry • There are different kinds of particles

  4. Modellen • For understanding • For prediction (science) • For manipulation (technology) • Reality………?

  5. Historisch (1) Leucippus/Demokrites 450 BC If you think atoms can stop their course, refrain from movement, and by cessation cause new kinds of motion, you are far astray indeed. Since there is void through which they move, all fundamental motes must be impelled, either by their own weight or by some force outside them. When they strike each other, they bounce off; no wonder, either, since they are absolute solid, all compact, with nothing back of them to block their path....

  6. Molecule formation According to Dalton (1810) Historically (2) Thomson model (1897) Rutherford sketch in alpha article (1911) motion???

  7. Bohr model Aim: qualitative understanding of emission and absorption Representation of Quantisation BUT: Particle model UNSUITED AS FIRST STEP TOWARD QUANTUM MECHANICAL MODEL

  8. Particles: questions ? ?

  9. Example 10: Imagine that we have “magic spectacles” through which we can see the air. Draw the air.

  10. Some air is sucked out from the top, draw the air remaining in the flask

  11. Student’s answers

  12. Essential Elements QM Model • Particle / Wave • Probability *

  13. De fuzzy ball Molecule formation by fuzzy and sticky atoms

  14. Visualisations of the wavefunction Electron wavefunctions visualized: the electron smeared out over the atom

  15. Probability: questions ? ?

  16. Classical probability A pen is somewhere on the chair, f(x) is the probability per cm to find it. Draw f(x).

  17. Solutions Two of many possibilities

  18. Question The pen can be on any of the four chairs

  19. A solution

  20. Another solution If the chance is higher that it was left on chair 4

  21. Question Draw the distribution of balls after 10 000 tries

  22. Quantum • Interference: The big difference nr 1 (…, complementariteit, entanglement, identical particles, …) The riddle of the destruction of possibilities

  23. Double slits Particles / waves / quantum’things’ Hit a two-slit diaphragm

  24. Double slits Which of the two images A or B shows interference?

  25. Interference: questions ? ?

  26. Quantum atoms Solutions of the SE

  27. Simplefied models The particle in a box

  28. The particle in a box Applications, eg: • Estimates of the size of an atom fromthe frequency of a spectral line • Calculation of the colour of organic dyes • Calculations of the strength of materials

  29. carotene

  30. crystals

  31. Questions / Discussion ? ?

  32. Images of atoms Project Modern Physics Dick Hoekzema Ed van den Berg Gert Schooten Centrum voor Betadidactiek Universiteit Utrecht www.phys.uu.nl/~wwwpmn

More Related