Grade 6 · Matter and Its Properties · States of Matter
Particles and States of Matter
Using the particle model to explain solids, liquids and gases.
Learning objectives
- Describe the arrangement of particles in solids, liquids and gases.
- Use the particle model to explain shape and volume.
- Explain what happens to particles when a substance is heated.
NGSS alignment
MS-PS1-1
Develop models to describe the atomic composition of simple molecules and extended structures.
MS-PS3-4
Plan an investigation to determine the relationships among the energy transferred, the type of matter, the mass, and the change in average kinetic energy of the particles as measured by the temperature of the sample.
MS-PS1-4
Develop a model that predicts and describes changes in particle motion, temperature, and state of a pure substance when thermal energy is added or removed.
MYP criteria
- Criterion A — Knowing and Understanding
ENGAGE
Same stuff, three behaviours
EXPLAIN
The particle model
| State | Arrangement | Movement | Shape and volume |
|---|---|---|---|
| Solid | Regular, tightly packed | Vibrate about fixed positions | Fixed shape, fixed volume |
| Liquid | Close but disordered | Slide past each other | Takes container shape, fixed volume |
| Gas | Far apart, random | Fast, in all directions | Fills the container |
Heating transfers energy to the particles, so they move faster and, eventually, break free of the forces holding them together.
Interactive simulation · PhET
States of Matter: Basics
Heat and cool each substance and watch how particle arrangement and motion change.
While you explore
- How does particle spacing differ between solid, liquid and gas?
- What happens to particle speed as you add heat?
Key vocabulary
- Particle model
- The idea that all matter is made of tiny moving particles.
Practice questions
0/2 correct
Level 1
In which state are particles arranged regularly and only able to vibrate?
Level 2
A gas is compressed into a smaller container. What happens to the particles?
Reflect & track
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