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# What is everything made of?

Year 7 Chemistry · Particle theory

<!-- Speaker note: Students build the particle model's four key ideas (particles, space, motion, attraction) and match particle diagrams to solids, liquids and gases (AC9S7U05, node 1, a hinge node). About 25 minutes (Engage and Explore 7 min · Explain 6 min · Practise 5 min · Evaluate 3 min · Typical and Wider add about 10 min). -->

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## Today

**We are learning to** all matter is made of tiny particles with empty space between them, always moving and attracting each other. Match particle diagrams to solids, liquids and gases.

- I can state the four key ideas of particle theory.
- I can match a particle diagram to a solid, a liquid or a gas.
- I can describe how arrangement and motion differ between the three states.

<!-- Speaker note: Before class: This is a concept tutorial for introducing the model or revising it, not a replacement for the practical. Run it before hands-on work with states (melting ice, a sealed syringe of air). Set the width in the link you share: `?width=minimum`, `?width=typical` (the default) or `?width=wider`. Students can widen but not narrow. The node's response mode is consolidation, so the Practise step (six correct identifications, with feedback naming the particle feature each time) is part of the minimum path. Teacher: Evaluate: the 'At first I thought… Now I think…' sentence is worth collecting as an exit card. -->

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## Why it matters

> Water looks smooth and continuous. Zoom in about a billion times and the picture changes completely: that picture is the particle model, and the rest of chemistry is built on it.

<!-- Speaker note: Scientists explain how substances behave with a **model**: a simplified picture that is good at explaining and predicting. This lesson builds the particle model and its four key ideas. -->

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<span style="background:#dbeafe; color:#1a1a1a; border:1.5px solid #3b82f6; padding:6px 18px; border-radius:8px; font-size:1em; font-weight:500;">💬 Discussion</span>

## Engage: predict

**Zoom into a drop of water a billion times. What would you see?**

- Tiny particles with empty space between them
- Smooth water, all the way down
- Tiny particles floating in water
- Lots of tiny drops of water

<!-- Speaker note: What happens: Tiny particles with empty space between them, always moving. There is nothing between them, not even air. Take two or three predictions before anyone runs it. -->

<!-- Speaker note: Teacher: students lock in a prediction before the zoom lens opens. Ask who chose 'particles floating in water' and why; it is the most common answer. -->

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<span style="background:#fef3c7; color:#1a1a1a; border:1.5px solid #f59e0b; padding:6px 18px; border-radius:8px; font-size:1em; font-weight:500;">✍️ Activity</span>

## Explore it

{{embed: https://studio.learningwaypoints.com/tutorials/_playground-science/index.html?id=deck%2Fscience%2Fchemistry%2Fparticle-model%2Fstep-2&code=widget%3A+zoom%0Asamples%3A+ice%2C+water%2C+steam%0A}}

[Open this step in the tutorial](https://studio.learningwaypoints.com/tutorials/science/chemistry/particle-model/?full=step-2#step-2)

<!-- Speaker note: Look at each sample for a few seconds. Watch how the particles are spaced, and how they move. -->

<!-- Speaker note: Teacher: insist they watch the ice for a few seconds. 'Frozen still' is the misconception the second Explain question targets. -->

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<span style="background:#dcfce7; color:#1a1a1a; border:1.5px solid #22c55e; padding:6px 18px; border-radius:8px; font-size:1em; font-weight:500;">✅ Check</span>

## What happened?

* Tiny particles with empty space between them, always moving. There is nothing between them, not even air.

<!-- Speaker note: Reveal after running. Ask who predicted it, and what made them think so. -->

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<span style="background:#dcfce7; color:#1a1a1a; border:1.5px solid #22c55e; padding:6px 18px; border-radius:8px; font-size:1em; font-weight:500;">✅ Check</span>

## Between the particles

**What is between the particles?**

- Air
- Water
- Nothing: empty space

* Answer: Nothing: empty space

<!-- Speaker note: There is nothing between particles, not even air. -->

<!-- Speaker note: Teacher: the four key ideas are the hinge. Have students say them aloud in order: particles, space, motion, attraction. -->

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<span style="background:#dcfce7; color:#1a1a1a; border:1.5px solid #22c55e; padding:6px 18px; border-radius:8px; font-size:1em; font-weight:500;">✅ Check</span>

## Ice

**Do the particles in ice ever stop moving?**

- Yes, ice is frozen still
- No, they vibrate in place

* Answer: No, they vibrate in place

<!-- Speaker note: Even in a solid, particles vibrate. They never stop. -->

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<span style="background:#dcfce7; color:#1a1a1a; border:1.5px solid #22c55e; padding:6px 18px; border-radius:8px; font-size:1em; font-weight:500;">✅ Check</span>

## Same particles?

**Ice, liquid water and steam: are their particles the same?**

- No: steam particles are smaller
- No: ice particles are bigger
- Yes: only the arrangement and motion change

* Answer: Yes: only the arrangement and motion change

<!-- Speaker note: All three are made of the same water particles. -->

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<span style="background:#dcfce7; color:#1a1a1a; border:1.5px solid #22c55e; padding:6px 18px; border-radius:8px; font-size:1em; font-weight:500;">✅ Check</span>

## The four key ideas

**Which statements are part of particle theory?**

Groups: Part of particle theory · Not true

All matter is made of tiny particles. · There is empty space between particles. · Particles are always moving. · Particles attract each other. · Particles expand when they are heated. · There is air between the particles. · Particles in a solid do not move.

* Answer: All matter is made of tiny particles. → Part of particle theory; There is empty space between particles. → Part of particle theory; Particles are always moving. → Part of particle theory; Particles attract each other. → Part of particle theory; Particles expand when they are heated. → Not true; There is air between the particles. → Not true; Particles in a solid do not move. → Not true

<!-- Speaker note: Remember the four key ideas as: particles, space, motion, attraction. -->

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<span style="background:#dcfce7; color:#1a1a1a; border:1.5px solid #22c55e; padding:6px 18px; border-radius:8px; font-size:1em; font-weight:500;">✅ Check</span>

## Across the states

**Match each state to its particles: arrangement, motion and attraction.**

| | |
|---|---|
| `Solid` | A. Far apart, moving fast in all directions, very weak attraction |
| `Liquid` | B. Close together in a fixed pattern, vibrating in place, strong attraction |
| `Gas` | C. Close together with no pattern, sliding past each other, weaker attraction |

* Answer: Solid → B. Close together in a fixed pattern, vibrating in place, strong attraction; Liquid → C. Close together with no pattern, sliding past each other, weaker attraction; Gas → A. Far apart, moving fast in all directions, very weak attraction

<!-- Speaker note: The three states differ in the same three ways: arrangement, motion and attraction. -->

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<span style="background:#fef3c7; color:#1a1a1a; border:1.5px solid #f59e0b; padding:6px 18px; border-radius:8px; font-size:1em; font-weight:500;">✍️ Activity</span>

## name that state

{{embed: https://studio.learningwaypoints.com/tutorials/_playground-science/index.html?id=deck%2Fscience%2Fchemistry%2Fparticle-model%2Fstep-4&code=widget%3A+identify%0Aneed%3A+6%0A}}

[Open this step in the tutorial](https://studio.learningwaypoints.com/tutorials/science/chemistry/particle-model/?full=step-4#step-4)

<!-- Speaker note: Each round shows a new substance through the zoom lens. Is it a solid, a liquid or a gas? What this step is for: Reliable matching of diagrams to states needs practice with feedback that names the particle feature every time. -->

<!-- Speaker note: Teacher: six correct, not six in a row. Listen for students naming a feature, not just a state. -->

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<span style="background:#dcfce7; color:#1a1a1a; border:1.5px solid #22c55e; padding:6px 18px; border-radius:8px; font-size:1em; font-weight:500;">✅ Check</span>

## Elaborate: explain three things about ice

**For each property of ice, choose the particle explanation.**

Groups: Its particles are held in fixed positions by strong attraction · Its particles are packed closely, with very little space between them · Its particles vibrate more as they warm, until they break free of their positions · Its particles are far apart and move freely · Its particles get bigger when warmed

Ice keeps its shape on a plate. · You can't squash an ice cube. · An ice cube held in your hand starts to melt.

* Answer: Ice keeps its shape on a plate. → Its particles are held in fixed positions by strong attraction; You can't squash an ice cube. → Its particles are packed closely, with very little space between them; An ice cube held in your hand starts to melt. → Its particles vibrate more as they warm, until they break free of their positions

<!-- Speaker note: Each property comes from one particle feature: arrangement, motion or attraction. What this step is for: Explaining properties in particle language is the move from describing the model to using it. -->

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<span style="background:#fef3c7; color:#1a1a1a; border:1.5px solid #f59e0b; padding:6px 18px; border-radius:8px; font-size:1em; font-weight:500;">✍️ Activity</span>

## Elaborate: build a state

{{embed: https://studio.learningwaypoints.com/tutorials/_playground-science/index.html?id=deck%2Fscience%2Fchemistry%2Fparticle-model%2Fstep-6&code=widget%3A+build%0A}}

[Open this step in the tutorial](https://studio.learningwaypoints.com/tutorials/science/chemistry/particle-model/?full=step-6#step-6)

<!-- Speaker note: Choose how close the particles are and how they move. Try the combinations that don't make a real state too, and read what the board says. What this step is for: Spacing and motion go together: building the states from the two features shows why some combinations never happen. -->

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<span style="background:#dcfce7; color:#1a1a1a; border:1.5px solid #22c55e; padding:6px 18px; border-radius:8px; font-size:1em; font-weight:500;">✅ Check</span>

## What it explains

**Does the particle model explain it?**

Groups: Explained by the model · Not explained

Why a gas spreads to fill its container · Why you can smell perfume from across a room · Why copper is orange-brown · Why solids keep their shape · What particles themselves are made of · Why some substances are poisonous

* Answer: Why a gas spreads to fill its container → Explained by the model; Why you can smell perfume from across a room → Explained by the model; Why copper is orange-brown → Not explained; Why solids keep their shape → Explained by the model; What particles themselves are made of → Not explained; Why some substances are poisonous → Not explained

<!-- Speaker note: The model explains how substances behave, not everything about them. -->

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<span style="background:#dcfce7; color:#1a1a1a; border:1.5px solid #22c55e; padding:6px 18px; border-radius:8px; font-size:1em; font-weight:500;">✅ Check</span>

## The evidence

**In 1827 the botanist Robert Brown saw tiny grains from pollen jiggling in water under a microscope, in random directions, with nothing stirring the water. In 1905 Albert Einstein explained it with particles. What causes the jiggling?**

- The grains are alive and swimming
- The water is flowing slowly
- Water particles are always moving and keep bumping into the grains

* Answer: Water particles are always moving and keep bumping into the grains

<!-- Speaker note: This is Brownian motion: millions of tiny bumps from moving water particles. It was early strong evidence that particles are real and always moving. -->

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<span style="background:#dcfce7; color:#1a1a1a; border:1.5px solid #22c55e; padding:6px 18px; border-radius:8px; font-size:1em; font-weight:500;">✅ Check</span>

## Elaborate: designing with materials

**Match each design choice to the particle reason.**

Groups: A gas can be squashed, so it cushions bumps · A liquid hardly squashes, so a push at one end moves the other end straight away · Solid particles are held in fixed positions, so the shape stays under a load · Its particles are lighter

Bike tyres are filled with air, not water. · Car brakes use a liquid in the pipes to push the brake pads. · Bridge beams are made of solid steel.

* Answer: Bike tyres are filled with air, not water. → A gas can be squashed, so it cushions bumps; Car brakes use a liquid in the pipes to push the brake pads. → A liquid hardly squashes, so a push at one end moves the other end straight away; Bridge beams are made of solid steel. → Solid particles are held in fixed positions, so the shape stays under a load

<!-- Speaker note: What this step is for: Designers in Design and Technologies choose solids, liquids and gases for exactly these particle reasons. -->

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## Evaluate: look back

Go back to your prediction in Engage. Was matter smooth, drops, particles in water, or particles with empty space? Write one sentence: "At first I thought… Now I think… because…"

**Revision summary**

- All matter is made of tiny particles; there is empty space between them; they are always moving; they attract each other.
- **Solid:** close together in a fixed pattern, vibrating in place.
- **Liquid:** close together with no pattern, sliding past each other.
- **Gas:** far apart, moving fast in all directions.
- There is nothing between particles: not air, not water.

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<span style="background:#dcfce7; color:#1a1a1a; border:1.5px solid #22c55e; padding:6px 18px; border-radius:8px; font-size:1em; font-weight:500;">✅ Check</span>

## Exit ticket

**Name the four key ideas of particle theory.**

* All matter is made of particles; there is empty space between them; they are always moving; they attract each other.

<!-- Speaker note: Students answer on paper or a mini whiteboard before the reveal. Anyone who cannot answer needs the main idea again next lesson. Where this leads: Next: node 2 uses the diagrams to reason (why gases fill containers, why solids keep their shape). Node 3 explains properties such as compressibility and density. In class: follow with real samples (an ice cube, water, a sealed syringe of air) and ask students to draw the particle view of each. -->