Phase Change Triangle Worksheet
Phase Change Triangle
Thermal Energy & States of Matter Investigation
Name:
Date:
Period:
Score:
Directions: Write the correct state of matter in each blank box at the triangle's vertices, and track the flow of thermal energy.
Red = Heat Added
Blue = Heat Removed
THERMAL ENERGY TRANSFER Melting (Heat Added) Freezing (Heat Removed) Sublimation (Heat Added) Deposition (Heat Removed) Vaporization / Boiling (+Heat) Condensation (Heat Removed)
Phase Change Analysis
Identify whether thermal energy is added (+) or removed (−):
| Process | Initial → Final State | Energy (+ / −) |
|---|
| Melting | Solid → Liquid | Added (+) |
| Condensation | ________ → ________ | ______________ |
| Sublimation | ________ → ________ | ______________ |
| Freezing | ________ → ________ | ______________ |
| Deposition | ________ → ________ | ______________ |
Critical Thinking
1. When water droplets appear on cold soda, what phase change happened? Was heat added or removed?
2. Describe how particle motion and spacing change during sublimation:
3. Frost forming directly on a winter windowpane is an example of which phase change?
States Word Bank: Gas Liquid Solid
NGSS MS-PS1-4 • Structure & Properties of Matter
