Transcript Class 11

How do we detect gamma rays?
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Review:
What is each peak?
Why are they there?
Calculate the location of the Compton edges and backscattering!
1.17 MeV and
1.33 MeV
Five Minute Questions
Review gamma spectroscopy data
Photoelectons
Compton Edge
Back Scattering
Pair Production
X-ray Production
Simple models of atoms – Evolution in our thought…
Thompson’s plum pudding model – photon spectrum?
Rutherford Scattering
Bohr’s atom in all its glory
X-ray spectra
Five Minute Question #1.
•Gauss’ Law
 
q in
  E  da
o
You have sphere of uniform charge. (The charge is spread out evenly throughout the sphere.) The charge is Q. The radius is R.
•What is the Electric Field strength at point A where the distance from A to the center of the sphere is r A (rA > R).
•What is the Electric Field strength at point A where the distance from A to the center of the sphere is r B (rB = R).
•What is the Electric Field strength at point A where the distance from A to the center of the sphere is r C (rC < R).
Five Minute Question #2
Start the calculation to find the radius of orbit of a geosynchronous satellite. (Start with Newton’s second Law.
Then use Newton’s law of Gravity and centripetal acceleration!)
Chapter 6 – Based on experiments, how can we learn about
atoms and their internal structure?
Model #1 – Plum Pudding
What force does a raisin (q=-e) at a radius, r, feel from the pudding?
•Attractive to center
•No force at the center
•Oscillatory – specific frequency