Unit 5: Light as a particle

Click here for the Light as a Particle Unit practice problems


Lesson 1
Quantization of Light
  • 1.1 The Blackbody Radiation Problem
  • 1.2 Plank's Solution
  • 1.1 and 1.2 Due May 13
Lesson 2
The Photoelectric Effect
  • 2.1 The Photoelectric Effect
  • 2.2 Einstein's Explination of the Photoelectric Effect
  • 2.3 Millikan's photoelectric experiment
  • 2.1, 2.2 Due May 14
  • 2.3 Due May 23
Lesson 3
Light Spectra and Excitation States
  • 3.1 Types of Spectra
  • 3.2 Bohr's explanation of elemental spectra
  • 3.3 The Frank-Hertz Experiment
  • 3.1 and 3.2 Due May 15
  • 3.3 due May 16
Lesson 4
The Compton Effect
  • 4.1 The Compton Effect
  • 4.2 The Compton Formula
  • 4.1 and 4.2 Due May 27
QUIZ: Lessons 1-4
  • Quiz will be written in class on Tuesday, May 21. If you are not in class on Tuesday, May 21, the rewrite day is after school on Wednesday, May 29. If you write the quiz in class on Tuesdat, May 21 and don't like your mark, you can also come in on Wednesday, May 29 to rewrite and attempt a better mark.
GRAD
  • Wednesday, May 22.
LAB: THE PHOTOELECTRIC EFFECT
  • Lab will be done during class time on Thursday, May 23. If you are not in class for the lab day, you must complete the lab in your own time at home.
    Instructions
    1. Download the lab sheet here
    2. open the PHET photoelectric effect simulation
    3. Start with a sodium cathode: using different light wavelengths (300 nm, 270 nm, 240 nm, 210 nm, 180 nm and 150 nm) adjust the battery voltage until the electrons just start to turn back. Record this voltage as the stopping voltage for each wavelength
    4. Repeat step 2 for calcium and the unknown metal cathodes
    5. Covert the wavelengths into frequencies (c=frequency x wavelength) and the stopping voltage to kinetic energy (Ek=qVstop)
    6. Plot a graph of kinetic energy versus frequency for each metal type (download graph paper here). Use the graph to determine the metal work function, threshold frequencies and Planck's constant.
    7. Answer questions 3 and 4

  • Lab report due: May 28
Lesson 5
The Wave Nature of Matter
  • 5.1 Wave nature of matter
  • 5.1 Due May 27
Unit Exam
  • Review in class Monday, May 27
  • Unit exam Tuesday, May 28