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Modern Physics (PC300)

Modern Physics (PC300). Class #8: Quantum Mechanics Born. Test Assessment. Photoelectric Effect. -. +. Photoelectric Effect: Intensity. Makes Sense: more photons - more electrons. Photoelectric Effect: Frequency. 1902: Lenard -. Maximum KE does not depend on intensity.

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Modern Physics (PC300)

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  1. Modern Physics(PC300) Class #8: Quantum Mechanics Born

  2. Test Assessment

  3. Photoelectric Effect - +

  4. Photoelectric Effect: Intensity Makes Sense: more photons - more electrons

  5. Photoelectric Effect: Frequency 1902: Lenard - Maximum KE does not depend on intensity 1905 Lenard - Nobel Prize

  6. 1905: Photoelectric Effect: Solution Classical electromagnetic theory has problems explaining the independence of Kmax and light intensity, the linear dependence of Kmax on light frequency and the instantaneous (10-9s) response of the photocurrent. Einstein - Light composed of irreducible "grains" - quanta (energy packets). 1921 Einstein - Nobel Prize 1905 What a year for Einstein http://www.aip.org/history/einstein/chron-1905.htm

  7. Photoelectric Effect: Work Functions (Kmax)

  8. Various Work Functions http://www.youtube.com/watch?v=m55kgyApYrY 1923 Millikan - Nobel Prize Why do different metals have different work functions?

  9. Problem Set for Wednesday • To answer the first two questions you will first need to do a Simulation. • Run the Photoelectric Effect program by following the steps below. • P:\Academic\White\PC301 Modern Physics 2013\Programs\Photoelectric\Photoelectric_en • Take data to answer the following question. • 1. Using five different wavelengths striking Sodium, calculate the ratio h/e. (Hint, make a graph in Excel of the Stopping Potential vs. frequency. Include this graph, with a trendline, in your homework solution. And remember, that all graphs need labels, a title, and a short caption…) • 2. Find the Workfunction for each of the six elements (most of which are metals…including the unknown) used in the simulation. Make a simple chart of your findings. Write a few sentences that clearly describe what procedure you followed and how you arrived at these conclusions.

  10. Sim #4: Photoelectric Effect P-Drive\White\Modern Physics\Programs\Petutor\CTWINX Click on Photo15.ctb then hit OK

  11. Lab 6 – Photoelectric Effect

  12. X Ray Production 1901 Roentgen - Nobel Prize

  13. EM Spectrum: X-Rays (Duane-Hunt Rule)

  14. Quantum Homework Questions Some Simulation Questions and an Electron Gun question Also… Thornton and Rex! "Yeah, well I got mine first Due Wed normal time

  15. 1897 - J.J.Thompson 1906 - Nobel Prize

  16. X Ray Production

  17. Measuring charge/mass (e/m) Electron beam Cathode Ray Cathode Ray Tube Derive in lab

  18. Lab ? - e/m setup

  19. 1909 - Robert Millikan Precise Measurement of e Oil Drop Experiment

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