Lesson
Wave Behavior
A door. A window. A brick wall. Same sound, same light: three completely different outcomes. Why?
Driving Question
How can a wave hit an object and still keep moving?
🔬 Learning Science Focus
🔍 Phenomenon First
🏷️ Label After Learning
🔄 Return to Source
📊 Quantitative Modeling
✅ Retrieval Practice
Learning Goals
What You'll Be Able to Do
By the end of this lesson, you will be able to:
Use models to show how waves are reflected, absorbed, or transmitted by different materials.
6.MS-PS4-2
Explain why a material looks transparent, translucent, or opaque.
6.MS-PS4-2
Track how a wave's energy is shared when it meets a surface.
6.MS-PS4-1
📚 Instructional Design
Why this section exists
- Name the targets before the lesson begins.
- Tie each goal to its Massachusetts standard (PS4-1, PS4-2).
Cognitive science
- Goal setting
- Advance organizers
Bloom's / DOK
- Understand to Analyze
- DOK 2 to 3, reaching 3 at the explain-why goal
Accessibility considerations
- Standard labeled on every card
- Short, single-action goal statements
- Icon paired with text
Key Vocabulary
Words You'll Meet
Choose a card to see what each word means.
📚 Instructional Design
Why this section exists
- Pre-teach the terms before they appear in context.
- Lower reading load in the explore sections that follow.
Cognitive science
- Pre-teaching vocabulary
- Reduced extraneous load
Bloom's / DOK
- Remember to Understand
- DOK 1
Accessibility considerations
- One card open at a time
- Click to reveal, no hover
- Plain, short definitions
Engage · Mystery
Three Objects. One Question.
You're outside a classroom. A door, a window, and a brick wall are between you and what's happening inside. Each surface interacts with sound and light differently.
The Wooden Door
You can hear voices inside, but you cannot see through the door.
Sound gets through. Light doesn't. Why?
Click to look closer
The Window
You can see inside clearly, and the room sounds a little louder near the glass.
Light passes through easily. Why?
Click to look closer
The Brick Wall
You cannot see through it, and you barely hear anything.
Most of the energy seems to just... stop. Where does it go?
Click to look closer
Same energy. The same sound waves and light waves from inside the classroom are hitting all three surfaces.
Why do the same waves behave so differently when they hit different materials?
The question: What determines what happens when a wave reaches matter? The wave didn't make a choice. The surface didn't choose. Something about the physics of each material is causing this, and this whole lesson is about figuring out what.
📚 Instructional Design
Why this section exists
- Open with a concrete puzzle: a mirror, a window, a wall.
- Surface that one wave meets different materials in different ways.
Cognitive science
- Curiosity gap
- Phenomenon-based learning
Bloom's / DOK
- Understand to Apply
- DOK 2
Accessibility considerations
- Everyday objects students already know
- Short opening prompt
- High-contrast object cards
Explore · What We Already Know
Waves Carry Energy: And Energy Has to Go Somewhere
Before we solve the mystery, there's one rule we need to remember.
Mechanical Waves
Need a medium to travel
Sound, water, and seismic waves all travel by pushing matter from particle to particle.
No medium → no mechanical wave. That's why you can't hear an explosion in space.
No medium → no mechanical wave. That's why you can't hear an explosion in space.
Electromagnetic Waves
Need no medium at all
Light, radio waves, and X-rays travel as disturbances in electric and magnetic fields, not in matter.
Empty space is fine. That's how sunlight crosses 93 million miles of vacuum to reach Earth.
Empty space is fine. That's how sunlight crosses 93 million miles of vacuum to reach Earth.
Waves carry energy.
Energy cannot be created or destroyed.
So when a wave reaches a surface, the energy must go somewhere.
In this lesson, you'll discover the three places that energy can go.
Energy cannot be created or destroyed.
So when a wave reaches a surface, the energy must go somewhere.
In this lesson, you'll discover the three places that energy can go.
📚 Instructional Design
Why this section exists
- Activate the prior idea that waves carry energy.
- Set energy conservation as the throughline for the lesson.
Cognitive science
- Prior knowledge activation
- Cause-and-effect modeling
- Misconception checking
Bloom's / DOK
- Understand to Analyze
- DOK 2
Accessibility considerations
- Builds on terms students already hold
- Short paragraphs
- Energy idea stated in plain language
Explore · When Waves Bounce
The Wave That Came Back
Stand in a canyon and shout. A few seconds later, you hear your own voice return. How did the sound come back?
You shout in a canyon. Your voice comes back a moment later: the exact sound, delayed.
You stand in front of a mirror. Light bounces back and reaches your eyes; your reflection appears.
Think about it: What do you think is happening to the wave's energy at the moment it hits the surface? Make a prediction.
Now we have a word for it
Reflection happens when a wave bounces off a surface instead of passing through it.
Echo in a canyon or caveSound
Your reflection in a mirrorLight
Bat echolocation: sound bounces off preySound
Sonar: bounces off the ocean floorSound
Concert halls shaped to reflect sound toward the audienceSound
Sunlight reflecting off water on a bright dayLight
Reflection: Sometimes energy bounces back.
But what if it doesn't?
Let's follow the energy next.
But what if it doesn't?
Let's follow the energy next.
📚 Instructional Design
Why this section exists
- Define reflection as wave energy bouncing back.
- Connect the term to the bounce-back observation students just made.
Cognitive science
- Cause-and-effect modeling
- Dual coding
- Misconception checking
Bloom's / DOK
- Understand to Analyze
- DOK 2
Accessibility considerations
- Predict before reveal, click not hover
- Labeled diagram paired with text
- Wrong predictions allowed, no penalty
Explore · When Wave Energy Stays Behind
The Wave That Disappeared, or Did It?
Leave a black car in the sun for an hour. Touch the seat. It's burning hot: no fire, no heater, just sunlight hitting dark fabric all afternoon.
A black car seat gets burning hot in sunlight. The light didn't bounce back; the seat isn't shiny. It didn't pass through; you can't see through it.
A recording studio lined with foam is eerily quiet. Sound enters the room and seems to vanish into the walls. Where did it go?
Step 1
Did the energy reflect back off the material?
❌ No: the seat isn't shiny
Step 2
Did the energy transmit through the material?
❌ No: you can't see through it
Step 3
So where did the energy go? Energy can't be destroyed; it must have gone somewhere.
→ It stayed inside the material
Now we have a word for it
Absorption is what happens when a wave's energy transfers into a material. The wave doesn't bounce back and doesn't pass through; its energy is taken in by the material, usually converted into thermal energy (heat).
Black car seat heating in sunlight
Black asphalt getting hot on a summer day
Acoustic foam quieting a recording studio
Carpet absorbing sound; hardwood floors are louder
Solar panels absorbing light and converting it to electricity
Wearing dark clothing in summer; absorbs more light energy
Absorption: Sometimes wave energy transfers into the material itself.
But not all energy stays behind.
Sometimes it keeps moving through the material instead.
But not all energy stays behind.
Sometimes it keeps moving through the material instead.
📚 Instructional Design
Why this section exists
- Show that absorbed energy is changed, not destroyed.
- Resolve the "it disappeared" framing in the section title.
Cognitive science
- Misconception checking
- Cause-and-effect modeling
Bloom's / DOK
- Understand to Analyze
- DOK 2
Accessibility considerations
- Title names the misconception directly
- Short cause-and-effect bullets
- High contrast text
Explore · When Waves Pass Through
The Wave That Kept Going
You're outside at night. Inside the house, the lights are on. You look through the window and see everything inside, clearly, in detail. Light waves traveled from inside, hit the glass, and kept moving, all the way to your eyes.
Light travels through window glass. The wave keeps moving through solid material and reaches your eyes on the other side.
A classroom door is closed. You can still hear muffled voices inside. Sound waves passed through the solid wood door.
Think about it: The energy didn't bounce back. And the glass didn't heat up. So where did the energy go? Make a prediction.
Now we have a word for it
Transmission is what happens when a wave passes through a material. The wave's energy continues moving, through the surface and beyond.
Light through window glass
Sound through a closed door or wall
Sound traveling through water
Light through eyeglass lenses
X-rays passing through soft tissue
Radio waves passing through walls
Transmission: Some energy passes straight through the material.
But how much gets through isn't the same for every material. Let's compare three different cases.
But how much gets through isn't the same for every material. Let's compare three different cases.
📚 Instructional Design
Why this section exists
- Define transmission as energy passing through a material.
- Separate "passed through" from "nothing happened to it".
Cognitive science
- Cause-and-effect modeling
- Dual coding
- Misconception checking
Bloom's / DOK
- Understand to Analyze
- DOK 2
Accessibility considerations
- Predict before reveal, click not hover
- Labeled diagram paired with text
- Wrong predictions allowed, no penalty
Explore · How Much Gets Through?
Transparent, Translucent, and Opaque
Transmission turns out to exist on a spectrum. Some materials let all the light through. Some let a little through. Some let none through. Watch what happens to a beam of light as it hits three different panels.
👤
Transparent
Light passes through clearly.
Images stay sharp.
Images stay sharp.
Window glass
Clear water
Eyeglass lens
Plastic wrap
👤
Translucent
Some light passes through.
Images look blurry.
Images look blurry.
Frosted glass
Wax paper
Fog
Stained glass
👤
Opaque
Light cannot pass through.
No image forms.
No image forms.
Brick wall
Wooden door
Metal
Most clothing
Back to the hallway
The window next to the classroom door? Transparent: light fully transmits through. The wooden door? Opaque to light, but only partially opaque to sound, which is why you can still hear voices. The brick wall? Opaque to both.
Important: "Opaque" doesn't mean the energy vanished. It means light can't transmit through; the energy reflects or absorbs instead.
And most real materials do all three things at the same time, just in different proportions.
Let's see what that actually looks like.
And most real materials do all three things at the same time, just in different proportions.
Let's see what that actually looks like.
📚 Instructional Design
Why this section exists
- Classify materials by how much light passes through them.
- Link a material property to how the object looks.
Cognitive science
- Classification practice
- Comparison and contrast
- Misconception checking
Bloom's / DOK
- Understand to Analyze
- DOK 2
Accessibility considerations
- Side-by-side comparison cards
- Click to reveal, no hover
- Short, parallel bullet lists
Explore · Energy Tracker
Where Does the Energy Go?
Real objects almost never do just one thing. Select a material and watch how incoming wave energy divides among the three destinations. The question isn't which behavior; it's how much of each.
Explored
← Select a material above to begin
Did any material put 100% of its energy into just one category?
No. Every single material split its energy among all three destinations. What changes is the ratio.
A mirror mostly reflects. Black asphalt mostly absorbs. Window glass mostly transmits. But none of them does only one thing; they all reflect some, transmit some, and absorb some.
That's the key insight: real materials almost never do just one thing. The difference between them is how much energy goes to each destination.
A mirror mostly reflects. Black asphalt mostly absorbs. Window glass mostly transmits. But none of them does only one thing; they all reflect some, transmit some, and absorb some.
That's the key insight: real materials almost never do just one thing. The difference between them is how much energy goes to each destination.
📚 Instructional Design
Why this section exists
- Show reflection, absorption, and transmission share one wave's energy.
- Make conservation visible: the three amounts always add back to the whole.
Cognitive science
- Cause-and-effect modeling
- Dual coding
- Variable isolation, one material at a time
Bloom's / DOK
- Understand to Analyze
- DOK 2 to 3 when students reason from the model how material changes the split
Accessibility considerations
- Interactive model, click not hover
- Labeled outputs paired with the visual
- One variable changes at a time
Quick Recall
Brain Check
Pull this idea back from memory before we wrap up.
Quick Recall
Just a quick brain check before we move on. Not graded.
You are back in the hallway. Which material is transparent?
📚 Instructional Design
Why this section exists
- Pull the three behaviors back from memory before the quiz.
- Catch confusion early while it is low stakes.
Cognitive science
- Retrieval practice
- Generation effect
Bloom's / DOK
- Remember to Apply
- DOK 1 to 2
Accessibility considerations
- Ungraded and low stakes
- Immediate feedback
- Try-again allowed
Explain · Wrap-Up
Back to the Hallway
You started this lesson standing in a hallway, wondering why light and sound behaved differently when they reached different materials. Now you know the answer. Every surface reflects, absorbs, and transmits energy. What changes is how much of each happens.
Window
Light
Mostly transmitted. The glass is transparent; light waves pass through almost completely. That's why you can see the room inside clearly.
Sound
Some transmission, some reflection. Sound gets through more easily near the glass, but not as clearly as through the open door.
Door
Light
Mostly absorbed and reflected. Wood is opaque; light cannot transmit through. Your eyes see nothing but the door itself.
Sound
Partially transmitted. Some sound energy passes through the wood. That's why you can hear muffled voices, but the door absorbs and reflects most of it.
Brick Wall
Light
Mostly reflected and absorbed. Very little light transmits through a thick brick wall.
Sound
Almost entirely reflected and absorbed. Very little transmits. The density of brick reflects most sound energy back, and absorbs the rest.
The Answer
A wave can hit an object and still keep moving because transmission is always an option.
When a wave reaches matter, some of its energy can pass straight through; the wave doesn't have to stop.
The Bigger Picture
Most real objects do all three things at the same time.
When a wave reaches matter, its energy is almost always divided among:
Reflected
Transmitted
Absorbed
What Changes
The ratio. Each material just uses a different mix.
Window glassmostly transmits
Mirrormostly reflects
Black asphaltmostly absorbs
📚 Instructional Design
Why this section exists
- Return to the opening hallway puzzle with the new model.
- Apply reflection, absorption, and transmission to the mirror, window, and wall.
Cognitive science
- Schema building
- Elaboration
- Coherent narrative
Bloom's / DOK
- Understand to Analyze
- DOK 2 to 3 when students connect material properties to wave behavior
Accessibility considerations
- Callback to the concrete opening
- Short narrative
- Key terms defined in place
Evaluate · Quiz
Check Your Understanding
Ten questions covering everything you discovered. Answer every question, then submit.
Your score will not be sent
Your score will be sent to your teacher
0 / 10 selected
🧠 Show Your Thinking
Scientists don't just know the answer. They explain their thinking.
Write your own explanation first. Then submit your work to compare your thinking with a model answer.
In one or two sentences, explain what happens to a wave's energy when it hits a material, like light hitting a glass window. Use reflection, absorption, and transmission, and explain why the same wave can behave differently on a window, a door, and a brick wall.
One strong way to say it
When a wave hits a material, its energy is split three ways: some is reflected (bounces back), some is absorbed (turns into thermal energy inside the material), and some is transmitted (passes through and keeps moving). Energy is never created or destroyed, so it always has to go to one of those three places. Different materials just use a different mix: a window mostly transmits light, a mirror mostly reflects it, and a brick wall mostly reflects and absorbs it. If your answer names all three destinations and says the material changes the ratio, you have it.
📚 Instructional Design
Why this section exists
- End the lesson with the student building the three-destination energy model in their own words, not selecting it.
- Give the one place where the student generates the explanation rather than clicks.
Cognitive science
- Generation effect and self-explanation
- Cause-and-effect: tracing a wave's energy into reflection, absorption, and transmission with energy conserved
- Self-check reveal for comparison, ungraded
Bloom's / DOK
- Analyze to Evaluate
- DOK 3 - construct the energy-split mechanism and apply it across materials
Accessibility considerations
- Sentence-length response, not an essay
- Keyword scaffold ("energy")
- Model answer to compare against
🔍 The Mystery You Came In With
You started this lesson with one question: "How can a wave hit an object and still keep moving?" If you can explain it now, you've solved the mystery.
📚 Instructional Design
Why this section exists
- Check understanding of the three behaviors and transparent, translucent, opaque.
- Give feedback before students move on.
Cognitive science
- Retrieval practice
- Feedback loops
Bloom's / DOK
- Understand to Apply
- DOK 1 to 2
Accessibility considerations
- Answer explanations provided
- Plausible, evenly placed options
- Practice mode works on its own
Go Further
More Learning
You've explored how waves reflect, absorb, and pass through materials. Now put those three behaviors to the test in a game built around them.
📚 Instructional Design
Why this section exists
- Offer a natural next step for students who want to keep working with reflection, absorption, and transmission.
- Preview the Photon Runner game, which is built around the same three wave behaviors.
Cognitive science
- Interest-driven extension - optional pathway maintains intrinsic motivation
- Transfer - applying the three behaviors to new materials and predictions
Bloom's / DOK
- Bloom's: Apply to Analyze
- DOK 2 to 3 - the game requires predicting an outcome and checking it
Accessibility considerations
- Optional and self-paced
- No penalty for skipping
- Category color system matches the index page for consistent navigation
Connections
Connections
These lessons build on what you just learned about wave behavior.