Energy transfer→Particle motion→Arrangement changes
Material & environment Liquid
Live measurements
Dominant stateLiquid
Average particle speed1.00 units/s
Internal energy298 units
Density indicatorMedium
Melting point here0°C
Boiling point here100°C
Purple = solid-like, blue = liquid-like, orange = gas-like. Near a boundary, two phases can coexist.
Dashed links show temporary hydrogen bonds between nearby water molecules.
Temperature & motion history
TemperatureParticle motionWhole sample history
Camera & focus
No object trackedFree camera
TipTap scene objects
Zoom1.00×
Particle evidence guide
Solid
Particles vibrate in an organized lattice; attractions dominate.
Liquid
Particles remain close but exchange neighbors and flow.
Gas
Particles spread out, move rapidly, and collide with walls.
Phase boundary
Two arrangements coexist while transferred energy reorganizes particles.
Hydrogen bonding: water molecules form short-lived attractions. Heating breaks these networks more often; cooling lets a more organized network form.
Learning outcomes
- Compare particle arrangement and motion in solids, liquids, and gases.
- Explain temperature as a measure linked to average kinetic energy.
- Distinguish temperature change from a phase change.
- Predict how pressure shifts boiling and condensation.
- Use particle evidence to explain melting, freezing, vaporization, and sublimation.
Core idea: matter does not disappear during a phase change. The same particles rearrange as energy and intermolecular attractions compete.
Suggested experiments
- Heat water slowly through 100°C at one atmosphere.
- Increase pressure and observe the boiling boundary move.
- Compare nitrogen and water at room temperature.
- Use carbon dioxide at low pressure to explore sublimation.
Questions for exploration
- Why does a gas fill the available container?
- Why are liquids dense but able to flow?
- How can two phases exist at the same temperature?