📚 Topic Summary
The particle model of matter explains that all matter is made up of tiny particles that are constantly moving. The arrangement and movement of these particles determine whether a substance is a solid, liquid, or gas. In solids, particles are closely packed and vibrate in fixed positions. In liquids, particles are close but can move around. In gases, particles are far apart and move randomly and quickly. Understanding this model helps us predict how matter will behave when heated, cooled, or mixed.
🧪 Part A: Vocabulary
Match the term with its correct definition:
| Term |
Definition |
| 1. Solid |
A. Particles are far apart and move randomly. |
| 2. Liquid |
B. The change of state from a liquid to a gas. |
| 3. Gas |
C. Particles are closely packed and vibrate in fixed positions. |
| 4. Evaporation |
D. Particles are close but can move around. |
| 5. Condensation |
E. The change of state from a gas to a liquid. |
📝 Part B: Fill in the Blanks
Complete the paragraph using the words provided: matter, particles, vibrate, gas, liquid, solid.
All _________ is made up of tiny _________. In a _________, particles are closely packed and _________ in fixed positions. In a _________, particles are close but can move around. In a _________, particles are far apart and move randomly.
🤔 Part C: Critical Thinking
Explain how the particle model helps us understand why ice (solid) melts into water (liquid) when heated.