Unit 1 · Energy & Matter in My World · Week 1
Where does the warmth come from?
A hand-warmer gets hot in your pocket with no fire, no flame, and no batteries. Where does the warmth come from?
Start here
How we work this lesson (our expectations)
- Wonder out loud — questions are the work
- Use evidence, not guesses
- Reasoning > being first or fastest
- Supports are for everyone — open any you want
30-second check-in self-management
Before we start, notice your focus right now. On a scale of 1 (foggy) to 5 (sharp), where are you? Take one slow breath. If you're at a 1 or 2, that's okay — the steps below are small on purpose, and you can listen to any part with the Listen button.
Do-Now Quick recall
Pull from what you already know — no looking back. Retrieval makes ideas stick.
- Name two things that feel warm and two things that feel cold to you right now.
- When you rub your hands together fast, they get warmer. Where do you think that warmth comes from?
- Everything around you — air, water, your desk — is made of tiny pieces too small to see. What do we call those pieces? (Best guess is fine.)
The phenomenon
On a cold morning you snap a small metal disc inside a clear pouch. Cloudy crystals spread through the liquid, and the pouch turns warm in your hand — no fire, no plug, no batteries. Later you can drop it in boiling water and it becomes a clear liquid again, ready to reuse. Something is making heat appear, and the "stuff" inside is clearly changing. Our question: where does the warmth come from, if there is no flame?
You snap a metal disc inside a soft pouch. The liquid turns into solid crystals, and the pouch gets warm. No fire. No battery. The heat comes from somewhere. Where does the warmth come from?
Notice & Wonder. Write one thing you notice and one thing you wonder. Keep your wonder — we are answering it today.
Build it Two big ideas, one small step at a time
We will build the answer in steps. After each step there is a quick check before we move on.
Step 1 — Everything is made of particles
All matter — the pouch, the liquid, your hand, the air — is made of incredibly tiny particles. They are far too small to see, they are always moving, and how they are arranged decides whether something is a solid, a liquid, or a gas. In a solid the particles are locked in a pattern; in a liquid they slide past each other; in a gas they fly around freely.
All matter is made of tiny moving particles. In a solid they are packed in a pattern. In a liquid they slide around. In a gas they fly apart. Same particles — different arrangement.
Step 2 — Energy is what makes particles move and change
Energy is the ability to make something move or change. Thermal (heat) energy is really the motion of particles: the faster they jiggle, the warmer something feels. Energy is never made from nothing and never disappears — it transfers from place to place. So if the hand-warmer got warmer, energy moved into the warmth you feel — it had to come from somewhere inside the pouch.
Energy makes things move or change. Heat is just particles jiggling fast. Energy does not appear from nothing — it moves from one place to another. The warmth had to come from energy already inside the pouch.
Worked example — modeling the change (watch how an expert reasons)
Before the snap: the particles inside are spread out in a liquid, sliding past each other, holding energy in the way they are arranged (like a stretched spring holds energy).
The snap: the particles suddenly lock into a solid pattern.
The result: as they snap into place, the stored energy is released as motion — the particles around them jiggle faster — and faster jiggling is heat. So: stored energy → released as particle motion → you feel warmth. No energy was created; it was stored, then transferred.
Show the model as a picture Tier 2 · visual
Liquid (spread, holding stored energy) → snap → Solid (locked pattern) + heat released to surroundings. Draw three boxes left-to-right: "spread out + energy stored", "snapping into place", "locked + heat out (arrows leaving)".
Your turn Explain the phenomenon
Use a Claim–Evidence–Reasoning model to answer our question. Choose how you respond — all are equally valid.
The task: Where does the warmth come from? Make a claim, give evidence from what we built, and explain your reasoning using particles and energy.
I want sentence starters Tier 2 · frames
Claim: The warmth comes from ________.
Evidence: I know this because when the disc snapped, the particles ________.
Reasoning: This makes warmth because faster-moving particles ________, and energy was not created — it ________.
Word bank: particles · energy · stored · transferred · motion · solid · liquid · heat
Let's make it concrete first Tier 3 · re-teach
Analogy: Imagine a crowd standing loosely in a gym (a liquid). Someone yells "line up!" and everyone snaps into neat rows (a solid). To get into place, people bump and shove — that bumping is motion, and motion is heat. They didn't get energy from nowhere; the energy was in how spread-out they were, and lining up released it.
Fill in: The warmth comes from energy that was stored when particles were ____, and got released as ____ when they snapped into a ____.
Now say your answer out loud before you write it. One sentence is enough.
Push my thinking Extension
The hand-warmer can be "recharged" by boiling it. Using energy and particles, explain what boiling water does to the crystals — and where the energy you'll later feel as warmth is hiding while it waits in your pocket. Then design one question you could test about it.
Check yourself Did it click?
- describe matter as moving particles whose arrangement makes a solid, liquid, or gas;
- explain that heat is particle motion and energy transfers rather than appears;
- use a particle model to say where the hand-warmer's warmth comes from.
Where does the hand-warmer's warmth come from?
Re-teach: stored vs. created energy Tier 3
Energy is never created or destroyed — only moved or changed in form. Before the snap, energy was stored in the spread-out liquid particles (like a stretched rubber band). The snap into a solid releases that stored energy as motion, and motion you can feel is heat. Re-read option B — that's the model.
Reflect, then show what you know
Reflection metacognition + SEL
Which support did you use today (if any), and did it help? There's no wrong answer — noticing what helps you learn is a skill scientists use too.
Exit ticket — answer on paper or in your notebook.
- New In your own words, what is heat in terms of particles?
- New A gas is heated until it glows. What is happening to its particles?
- Spiral From the Do-Now: when you rub your hands together, where does the warmth come from? (Use the word energy.)
- Spiral Name one solid, one liquid, and one gas around you right now.
- Transfer An ice pack gets cold instead of warm. Predict: is energy moving into or out of the pack from your hand? Explain with particles.
Educator panel — facilitation, accommodations, answer key
At a glance
Standards: NGSS MS-PS1-1 (model the structure of matter — introductory), MS-PS3-3 / PS3.A (energy as particle motion; transfer, not creation). 3D: SEP Developing & Using Models · DCI PS1.A & PS3.A · CCC Energy & Matter. Throughline: launches the year-long "where did the energy/matter go?" question.
Materials (optional, fully digital-capable): reusable sodium-acetate hand-warmer to demo (or the embedded image/scenario); student notebook. No lab required.
Facilitation arc (Rosenshine)
- Launch the phenomenon before any vocabulary — let the question be theirs (3 min).
- Do-Now retrieval while you take attendance (3 min).
- Build Steps 1–2 with the worked example; stop and check after each (12 min).
- Differentiated CER practice — circulate; name which tier supports students reach for (15 min).
- Self-check + re-teach branch for any "A/C" responders (5 min).
- Brain break, reflection, exit ticket (10 min).
IEP / 504 accommodation cards
Common accommodations mapped to this lesson
| Accommodation | How it's already built in / what to do |
|---|---|
| Text read aloud | Every passage has a Listen button (TTS); the simplified toggle shortens it. |
| Reduced reading load | "Reading: Simplified" swaps in shorter plain-language text site-wide. |
| Chunking / extended time | Lesson is in small steps with checks; progress saves automatically — students can stop and resume. |
| Sentence frames / word bank | Tier-2 panel under the practice task provides both. |
| Concrete manipulatives / models | Tier-3 "gym crowd" analogy + cloze; offer the physical hand-warmer to hold. |
| Alternative response mode | Students may draw, speak/record, or write the CER — all accepted. |
| Behavior / focus (504, ADHD) | Named expectations (PBIS), the 30-sec check-in, and a built-in brain break. |
| Multilingual / EL | Simplified text, visuals carry meaning, word bank, and home-language reflection is allowed. |
Exit ticket answer key
- Heat is the motion (jiggling) of particles — faster motion = warmer.
- The gas particles move faster and spread further apart.
- Friction adds energy to your hands' particles, making them move faster (warmer); energy transferred from your muscles' motion.
- Any valid examples (e.g., desk = solid, water = liquid, air = gas).
- Energy moves out of your hand into the pack; your hand's particles slow (cooler) as energy transfers away. (Sets up endothermic change next week.)
Why it's designed this way
Phenomenon-first (NRC 2012); worked example fades support to manage cognitive load (Sweller); supports are universally available, not gatekept (UDL 3.0 / MTSS); retrieval Do-Now and a spiraled, interleaved exit ticket strengthen retention (Roediger & Karpicke; Rohrer); branching self-check turns assessment into next-step feedback (Black & Wiliam). The "ice pack" transfer item previews Week 2's endothermic change.