Summary
Students investigate the particle properties of waves by discharging electroscopes and take notes using the Cornell Note System. The teacher performs a demonstration of discharging an electroscope with light. The students investigate the photoelectric effect using a simulation. Then using the Cornell Note System students explore Rogentgen's and Compton's experiments. Students use the 3-2-1 strategy to share what they have learned about the particle properties of light.
Essential Question(s)
Is light a wave or a particle?
Snapshot
Engage
Students participate in two questions where they process different scenarios and discuss the difference between classical physics and quantum physics.
Explore
Students take notes using the Cornell Note System and focus on Max Planck’s work, colors emitted by iron rods, and ultraviolet catastrophe.
Explain
The students observe a teacher demonstration for discharging an electroscope with UV light. They also participate in a PhET Photoelectric Effect simulation.
Extend
Students use the Cornell Note System to take notes about Roentgen’s and Compton’s experiment.
Evaluate
Students answer 3-2-1 prompts to show what they know about light having particle properties.
Materials
Lesson Slides (attached)
Electroscope Investigation handout (attached, optional)
Teacher Demonstration Discharging an Electroscope with UV light handout (attached, optional)
PhET Simulation Photoelectric Effect handout (attached, one per student)
PhET Simulation Photoelectric Effect Teacher’s Guide handout (attached, optional)
Class set of electroscopes with rods and clothes and static tubes (Optional)
Teacher Demonstration:
Red laser
Green laser (optional)
UV light source 254 nm
Electroscope with zinc disk on top
Rubber rod
Wool cloth
Access to computers or computer lab
Science Notebooks
Paper (optional, multiple pages per student)
Optional Student Electroscopy Activity
Static tube
Electroscope
Ebony (or pvc) rod
Acrylic rod
Wool cloth
Silk cloth
Balloon (one per group, optional)
Cloth (one per group, optional)
Engage
15 Minute(s)
Use the attached Lesson slides to present the lesson.
Display slides 3-4 to introduce the essential question and learning objectives to the class.
Display slide 5 and introduce the thought questions to the class. Inform them you will show them two different scenarios. They will take some time to think about the questions, discuss it with those sitting around them, and then discuss it as a whole class. Students can use their Science Notebooks or notebook paper to work out the questions or record their thoughts. Read over the thought questions on the slide. Provide students with time to think about the two questions and discuss it with their neighbors. Ask for volunteers to discuss their thoughts and answers.
Display slide 6 and discuss with the class the difference between classical physics thinking and quantum physics thinking.
Display slide 7 and present the second thought question to the class. Provide students with time to think about the question. Ask for volunteers to discuss their thoughts and answers. Display slide 8 and provide students with a second question to consider.
Display slide 9 and discuss with the class the difference between classical physics thinking and quantum physics thinking.
Explore
20 Minute(s)
Display slide 10 and introduce the class to the Cornell Notes System instructional strategy. Have students draw the image (an upside-down T) from the slide on a blank page in their Science Notebook. Let the students know that they will want to leave two-three blank pages after their first diagram for more Cornell Notes later in the lesson.
Display slide 11 and have students fill in the right side of their Cornell Notes focusing on the big ideas from the information from the following slides. Introduce students to Max Planck’s Quantum Theory.
Inform students that a description of Planck’s work with blackbody radiation will be presented. Students should define a blackbody and give an example in their notes.
Display slide 12 and discuss colors of light emitted by iron rod. Students should note that objects emit light of greater intensity as their temperature increases.
Display slide 13 and inform the students that as they watch the video pay attention to the colors of light emitted by iron rods in the video. Show the video, Heating a Nail White Hot.
Display slides 14-15 and present the ultraviolet catastrophe. Students should note the meaning of the ultraviolet catastrophe and what caused it. Have students also note that energy is quantized and has a fundamental unit and may be calculated using the E=hf equation.
Display slide 16 and show the video, Planck’s Constant and the Origin of Quantum Mechanics. Start the video at the 3:04 mark and stop the video at 10:15 minutes.
Have students skip two-three pages in their Science Notebooks for further notes in the Extend section.
Display slide 17 and have students look over their notes. Have students write down the key concepts they learned from the last few slides. Once they have recorded their key concepts, have them write 2-3 sentences summarizing what they have learned. Ask for a few volunteers to share their summaries.
Explain
55 Minute(s)
Display slides 19-20 and on a clean page in their Science Notebooks (remind them to skip a few pages), have students record the definitions for conductors and insulators.
Display slide 21 and, using the electroscope from the class demonstration, have students sketch a diagram of the electroscope and label the following parts.
Conductor
Insulator
Top plate or ball
Stationary stem
Mobile rod
Plastic/rubber stopper
In a separate window, navigate to the Balloon and Static Electricity PhET simulation. You will do this activity as a teacher demonstration. Start and complete the activity before moving to the next slide.
Display slide 24 and perform a teacher demonstration of charging and discharging an electroscope using the Teacher Demonstration Discharging an Electroscope with UV Light handout.
Display slide 25 and show the Electrostatic Induction video.
This video is used to help students understand what they observed in the investigation.
Day 2
Display slide 27 and introduce the students to an investigation of the photoelectric effect using a Phet simulation. Pass out the PhET Photoelectric Effect handout to each student. Have students work in pairs and share laptops. Have students navigate to the link on the slide to access the simulation. Students will set up the simulation as instructed.
Show slide 28 and use the following 11 slides to help guide the students through the simulation.
First, make sure students have properly adjusted settings.
Have students complete experiment steps 1-3 and show slide 29.
Emphasize that now photoelectrons are produced and there is no current.
Have students complete experiment steps 4 and 5 and then show slides 30 and 31.
Emphasize that photoelectrons are produced, there is a current and the increasing the intensity causes the current to increase.
Have students complete experiment step 6 and show slide 32.
Emphasize that a single photon can produce a photoelectron.
Have students complete experiment step 7 and show slide 33.
Emphasize that red photons cannot produce photoelectrons at any intensity.
Have students complete experiment step 8 and show slide 34.
Emphasize that higher frequency photons produce photoelectrons with higher kinetic energy.
Have students complete experiment step 9 and show slide 35.
Emphasize the maximum wavelength of the photons that produced photoelectrons.
Have students complete experiment step 10 and show slide 36-39.
Emphasize the maximum wavelengths of the photons that produced photoelectrons for each metal.
Once the simulation is complete, display slide 40 and show the video Photoelectric Effect. Explain to the students that this is the experiment that goes with the simulation they just worked through.
Extend
15 Minute(s)
Have students get their Science Notebooks back out and open to the extra pages by their Cornell notes. Show slide 41 and remind students of the Cornell Note System. Have them draw a new diagram in their Science Notebook.
Display slide 42 and present Einstein's experiment and ideas. Students should note that Einstein applied Planck’s idea, the formula for photon energy and how the photoelectric effect demonstrates particle behavior, what a photon is and how classical wave theory was inconsistent with the observed effect.
Display slide 43 and emphasize the points on the slide.
Day 3
Display slide 44 and present Roentgen’s experiment. Students should note the detail of the experiment and that it supported particle-like behavior.
Display slide 45 and show the video How Does an X-ray Tube Work. Tell students this is similar to the device Roentgen used in his experiment.
Display slide 46 and present Comptons’ Experiment. Students should note the detail of the experiment and that it supports particle-like behavior.
Display slide 47 and show the video of Compton Experiment Animation. Explain to the students that this will help them understand Comptons’ Experiment.
Display slide 48 and have students look over their notes. Have students write down the key concepts they learned from the last few slides. Once they have recorded their key concepts, have them write 2-3 sentences summarizing what they have learned. Ask for a few volunteers to share their summaries.
Evaluate
15 Minute(s)
Display slide 49 and introduce the students to the 3-2-1 instructional strategy. Inform the students that they will use this strategy to assess what they have learned throughout this lesson. Students will address the following concepts in their Science Notebooks or on a sheet of notebook paper.
3 -Statements showing what you learned about light having properties of particles.
2- Questions you have about light having properties of particles.
1- Thing you found most interesting about light having properties of particles.
Resources
Bozeman Science. (2015, January 12). Electrostatic induction. YouTube. Video. https://www.youtube.com/watch?v=dwJ-MM7yu4E
Ionactive Consulting Limited. (2009, November 4). How does an X-ray tube work (radiation protection). YouTube. Video. https://www.youtube.com/watch?v=Bc0eOjWkxpU
Kids Fun Science. (2017d, October 6). Opposites attract static electricity experiment. YouTube. Video. https://www.youtube.com/watch?v=l5JjkoDyHlM
K20 Center. (n.d.). 3-2-1. Strategies. https://learn.k20center.ou.edu/strategy/117
K20 Center. (n.d.). Cornell notes system. Strategies. https://learn.k20center.ou.edu/strategy/56
PBS Space Time. (2016b, June 22). Planck’s Constant and the origin of quantum mechanics. YouTube. Video. https://www.youtube.com/watch?v=tQSbms5MDvY
Rebiaz, Catatan Si. (2021c, December 6). Compton Experiment Animation | 12th class physics. YouTube. Video https://www.youtube.com/watch?v=zTzJJ9lGP0U
The Action Lab. (2021a, July 8). Knocking electrons with light-the photoelectric effect. YouTube. Video. https://www.youtube.com/watch?v=oYnp0WZDhYQ
University of California. Berkeley. College of Chemistry. (2012, August 15). Photoelectric effect. Video. YouTube. https://www.youtube.com/watch?v=kcSYV8bJox8
University of Colorado at Boulder. (n.d.). Balloons and static electricity. PhET. Interactive Simulations. https://phet.colorado.edu/en/simulations/balloons-and-static-electricity/about
University of Colorado at Boulder. (n.d.). Photoelectric effect. PhET. Interactive Simulations. https://phet.colorado.edu/en/simulation/legacy/photoelectric
Walding, Richard. (2019a, June 26). Heating a nail white hot (NCPQ). YouTube. Video. https://www.youtube.com/watch?v=1wMoR2y01Nw