2.1
Solids, liquids and gases
Everything is made of particles. How they are arranged and how they move explains solids, liquids and gases.
2.2
Changes of state
Melting, freezing, evaporating, condensing and sublimation, explained by what the particles do.
2.3
Gas pressure
Gas particles hit the walls of their container. Every hit is a push, and together they make gas pressure.
2.4
Diffusion and Brownian motion
Particles spread out because they are always moving, and Brownian motion shows us that they are there.
Daily 5
Five quick diagram questions a day from this unit. The ones you get wrong come back sooner. Progress saves in this browser.
What this unit covers
Mapped to the KS3 national curriculum (Chemistry: the particulate nature of matter; Physics: matter).
| Programme of study | Lesson |
|---|---|
| the properties of the different states of matter in terms of the particle model, including gas pressure | 2.1, 2.3 |
| changes of state in terms of the particle model | 2.2 |
| conservation of mass on changes of state; density differences between states | 2.1, 2.2 |
| diffusion in terms of the particle model; Brownian motion in gases | 2.4 |
| changes with temperature in the motion and spacing of particles | 2.2, 2.3 |