State Changes & Phase Transitions

MS-PS1-4 · Why does a balloon shrink when you put it in the freezer?

📋 Instructions

Driving Question: What happens to particles during phase changes?

1. Click Play to slowly add energy and watch particles change state.

2. Watch the heating curve — notice the flat plateaus during phase changes.

3. Switch substances to compare melting/boiling points.

4. During plateaus: temperature stays constant but particles rearrange!

3 J/s
Particle View
Heating Curve

Measurements

Temperature:-20°C
State:Solid
Energy Added:0 J
Phase:Below melting point

Key Concepts

Melting: solid → liquid (energy breaks rigid bonds)
Boiling: liquid → gas (energy overcomes intermolecular forces)
Latent heat: energy absorbed without temperature change during transitions
Plateau: flat region on heating curve = phase change in progress
📊 Data JournalTrial 0
# Substance Temp °C State Energy J Phase

🤔 Predict

If you keep adding energy to ice at -20°C, predict what the temperature vs energy graph will look like. Will it be a straight line?

👀 Observe

Watch the heating curve as energy is added. Where does the temperature stop rising? What are the particles doing during those flat sections?

💬 Explain

Why does the temperature stay constant during melting and boiling even though energy is being added? Where does that energy go?