wunder beta🟢 The Particle Model
One simple picture explains it all: why solids hold shape, liquids flow, gases squash, and smells spread. Meet the particle model of matter.
What you’ll learn
- The ModelUnderstand what the particle model is and how it pictures solids, liquids, and gases.The particle model says all matter is made of tiny particles, and their arrangement and movement explain how it behaves. Solids have particles packed in fixed rows, liquids have particles that slide, and gases have particles far apart and moving freely.
- Explaining StatesUse the particle model to explain the shape, flow, and volume of each state.Solids keep their shape because their particles are locked in place. Liquids flow because their particles slide past one another. Gases fill and squash because their particles are far apart. The same model explains all three.
- Explaining BehaviourUse the particle model to explain compression of gases and diffusion.Gases can be compressed because there are big gaps between their fast-moving particles, while solids and liquids cannot. Those same fast, free particles mix and spread by diffusion, which is why smells travel across a room.
Questions this course answers
What is the particle model?
The particle model pictures all matter as tiny particles, and how they are arranged and move explains the behaviour of solids, liquids, and gases.
In the particle model, how are a gas's particles arranged?
In a gas the particles are far apart and move fast in all directions, so a gas fills its container and can be squashed.
Why does a solid keep its shape?
A solid's particles are locked in a fixed pattern and can only vibrate, so they cannot move around and the solid keeps its shape.
Which state can be squashed into a smaller space?
A gas can be squashed because there are big gaps between its particles. Solids and liquids have almost no gaps.
Why can a gas be compressed but a liquid cannot?
Gas particles have large gaps that can be squeezed closer, while a liquid's particles are already close together, so it hardly compresses.
How does the particle model explain why smells spread across a room?
Gas particles move fast and freely, so they mix and diffuse, spreading a smell from where there are many particles to where there are few.
Grounded in trusted sources
- Royal Society of Chemistry
- BBC Bitesize
- Britannica
- American Chemical Society
Every Wunder lesson is built from real, reputable sources — never invented.
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