CHM003 · Discovery & Lab Basics · Classes 3–7
States of Matter Particle Model
Objective: To see how water particles are arranged and move as a solid, a liquid and a gas.
🧰 Virtual materials and apparatus
- Virtual box of water particles
- Thermometer
📐 Formulas and SI units
water: solid ≤ 0 °C < liquid < 100 °C ≤ gas
v_rms = √(3RT/M)
💡 Theory
All matter is made of tiny particles that are always moving. In a solid they vibrate in fixed places; in a liquid they are close together but slide past each other; in a gas they are far apart and move fast. Heating gives particles more energy, so water changes from ice to water at 0 °C and to steam at 100 °C.
🪜 Guided virtual procedure
- Start at 25 °C and watch the particles slide past each other.
- Lower the temperature below 0 °C and watch them lock into place.
- Raise it above 100 °C and watch them spread out.
- Note how the speed readout changes with temperature.
- Fill the observation table.
📋 Observations Simulated values
✅ Result and conclusion
At 25 °C water is a liquid; its molecules move at about 640 m/s on average but stay close together.
🔬 Real lab vs simulation
Real particles are far too small to see; the model shows a few dozen, enlarged and slowed down. Changes of state also depend on pressure.
⚠️ Safety
Hot water and steam burn: changes of state with heating are shown only on screen here.
❓ Quick check
1. In which state are particles farthest apart?
2. Water freezes at…
3. Heating makes particles…
🏋️ Practice
EasyWhat state is water at 50 °C?
Answer: Liquid
MediumWhy can a gas fill any container?
Answer: Its particles move freely and far apart
ChallengeWhat happens to particles when ice melts?
Answer: They leave fixed places and slide past each other