K323 / 2027

Chapter 7

Kinetic particle model of matter

A particle model connects observations with an explanation.

Learn to explain a material's properties and temperature in terms of its particles.

Includes states of matter, temperature, Brownian motion and gas pressure. For K323 (2027) / 6091 (2026).

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  1. States of matter

    Explain shape, volume, flow and compressibility using the particle model.

  2. Temperature and particle motion

    Relate a temperature increase to greater average particle kinetic energy.

  3. Brownian motion

    Separate the visible observations from the inference about unseen molecular motion.

  4. Gas pressure

    Explain pressure using collisions with walls and reason about controlled changes.

Syllabus coverage

This chapter covers Kinetic particle model of matter, topic 7(a-e), in the K323 syllabus (2027) and 6091 (2026).

View the learning outcomes
7(a)
Compare physical properties of solids, liquids and gases. States of matter
7(b)
Explain the properties of all three states using particle arrangement, motion, forces and distances. States of matter
7(c)
Infer random molecular movement from observations in a Brownian motion experiment. Brownian motion
7(d)
Relate a temperature increase to greater average particle kinetic energy. Temperature and particle motion
7(e)
Explain gas pressure in terms of particle motion. Gas pressure