1. Modern Physics (PC300) Class #9: Introductory Stuff towards Quantum Mechanics

2. Quantum Homework Questions Photoelectric Also some from Thornton and Rex– Due Wednesday "Yeah, well I got mine first

3. Experimental basis for the introduction of a quantum theory. Photoelectric Effect – Almost done X-Ray Production Charge/mass of an electron Blackbody Radiation Stefan-Boltzmann law Wien’s Displacement Law Ultraviolet Catastrophe Review what we know about how gamma particles are absorbed by matter. Photoelectric effect Compton Scattering Pair Production

4. Photoelectric Effect + -

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

6. Photoelectric Effect: Frequency Maximum KE does not depend on intensity1902: Lenard - 1905 Lenard - Nobel Prize

7. Photoelectric Effect: Work Functions (K max )

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

10. Lab – Photoelectric Effect

11. X Ray Production 1901 Roentgen - Nobel Prize

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

13. X Ray Production

14. 1897 - J.J.Thompson 1906 - Nobel Prize

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

16. Lab ? - e/m setup

17. 1909 - Robert Millikan Precise Measurement of e Oil Drop Experiment

20. Black Body Radiation “An idealized object that absorbs all the electromagnetic radiation falling on it, regardless of frequency.” Early observations – hot metals

21. Ultraviolet Catastrophe Classical Physics – Rayleigh-Jeans Law

22. 1900 - Planck’s Law Unusual (Crick-Watson) type approach: -> Equation that fits data -> Make it work -> Could not justify finding 1918 Planck - Nobel Prize

23. Lab – Blackbody Radiation Extension - Pasco Setup