States of Matter Simulator
Heat and cool particles to see solid, liquid and gas behaviour and phase changes.
Choose a substance, then press Solid, Liquid or Gas, or use the heater and cooler. Watch the atoms freeze into a crystal, flow like a liquid or fly around as a gas. Squeeze the lid to change the pressure.
About the States of Matter Simulator
Free states of matter simulation. Add or remove heat and watch particles freeze, melt and boil, with real attraction forces between them. Great for chemistry and physics classes. Built for chemistry, the states of matter simulator runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
Heat and cool particles to see solid, liquid and gas behaviour and phase changes. Use it to explore chemistry ideas at your own pace, then check what you found against the key ideas further down this page.
How to use the States of Matter Simulator
- Use the controls to change Substance, Set the state, Heater (+) / Cooler (−), Container volume. The simulation reacts instantly.
- Pick an option such as Neon, Argon, Oxygen, Water to switch modes or load an example.
- Press "Reset" to start, reset or change what is happening.
- Where you see a glowing handle, object, weight or atom, drag it with your mouse or finger. Everything responds in real time.
- Watch the readouts and graphs update as you experiment, and compare what you see with the key ideas below.
Things to try
- Cool to 25 K and watch the solid form.
- Heat slowly through melting.
- Jump to Gas and watch the particles spread.
- Watch the bonded particle percentage.
Key ideas you can learn
- In a solid, particles vibrate in fixed positions.
- In a liquid, particles slide past each other but stay close.
- In a gas, particles have enough energy to escape each other's attraction and fill the container.
Where this is used in the real world
Understanding solid, liquid and gas behaviour helps in cooking, weather, refrigeration, metal casting and materials science.
Who is this simulation for?
Chemistry students from middle school to university, teachers who need a virtual demonstration, and anyone without access to a lab. It is safe, free and repeatable as many times as you like.
For teachers: project it on the board, let students predict what will happen, then run it together. For students: change one thing at a time and write down what changes.
Frequently asked questions
What happens to particles when a solid melts?
They gain enough kinetic energy to break out of their fixed positions, though they stay close together as a liquid.
Why does temperature stay flat during a phase change?
The added energy goes into breaking attractions between particles instead of making them move faster, so the temperature holds steady until the change is complete.
Is the States of Matter Simulator free to use?
Yes. It is completely free, with no signup, no download and no ads inside the simulation. It runs in your web browser.
Does the States of Matter Simulator work on a phone or tablet?
Yes. It uses touch as well as the mouse, so you can drag objects with your finger. A larger screen makes the controls easier to see.