Authentic Lessons for 21st Century Learning

Beyond the Slinky®, Part 1

Qualitative Characteristics of Waves

Danny Mattox, Bj Sneed, Heather Shaffery, Anna Rodriguez | Published: June 2nd, 2022 by K20 Center

  • Grade Level Grade Level 6th, 7th, 8th, 9th, 10th, 11th, 12th
  • Subject Subject Science
  • Course Course Chemistry, Physical Science
  • Time Frame Time Frame 150 minutes
  • Duration More 2-4 class periods


In this lesson, students will investigate the qualitative characteristics of waves. The next lesson in this three-part series focuses on the quantitative characteristics of waves.

Essential Question(s)

What is a wave?



Students predict the heating pattern in a microwave and then see if their predictions are correct.


Students investigate waves in a series of stations set up around the classroom.


Students discuss what they observed at the stations as a class.


Students complete a Card Sort activity to learn about the wavelengths of the electromagnetic (EM) spectrum and the frequency and amplitude of sound waves.


Students use the Claim, Evidence, Reasoning (CER) strategy to revise their original thoughts on how microwaves work.


  • Lesson Slides (attached)

  • Microwave Demonstration handout (attached; one per student)

  • Wave Stations handout (attached; one per student)

  • 3-2-1 handout (attached; one half-sheet per student)

  • Card Sort With Cut Lines (attached; one card set per student pair)

  • Card Sort Key (attached)

  • Claim, Evidence, Reasoning (CER) handout (attached; one per student pair)

  • Microwave oven

  • Cardboard, cut into a square to fit in the bottom of the microwave

  • Giant chocolate bars, refrigerated

  • Wax paper

  • Metal hanger

  • String/twine

  • Pencils

  • Pie plates

  • Tuning forks

  • Prism

  • Water

  • Styrofoam cups

  • Paper clips

  • Eyedropper

  • Rulers

  • Rubber bands of various sizes/thickness

  • Scissors

  • Flashlight (non-LED works best)

  • Straws


Introduce the lesson using the attached Lesson Slides. Display slide 3 to share the essential question and go to slide 4 to review the lesson objectives with students.

Go to slide 5. Pass out the attached Microwave Demonstration handout to each student.

  1. Make sure the microwave is set up as described in the note above.

  2. Ask students to draw a diagram of the microwave and depict how things are heated inside.

  3. Place 3–5 refrigerated chocolate bars on a sheet of wax paper, then place them on the cardboard in the microwave. The chocolate should cover most of the cardboard so that you can see the heating pattern clearly.

  4. Reduce the microwave's power. If your microwave uses a power scale of 1–10, choose a setting of 3–4, or 30–40 percent of the microwave's total power.

  5. Ask students to draw and label the chocolate and the cardboard. Then, have students write one or two sentences to predict what will happen when the chocolate is microwaved at lower power while not rotating.

  6. Turn on the microwave for 10–15 seconds.

  7. Check the chocolate for melted spots.

  8. Repeat steps 6 and 7 until there are some obviously melted spots in the chocolate.

  9. Mark the melted spots with a toothpick and measure the distance between melted spots.

  10. Without offering an explanation, discuss the results with the class.