Pearson Edexcel International GCSE in Physics · 4PH1
Topic 5 · Solids, liquids and gases
Density and pressure, pressure in fluids, changes of state, specific heat capacity, and the particle model that explains gas pressure and the two gas laws.
7 lessons, covering 22 specification statements: 5.1 · 5.3 · 5.4 · 5.5 · 5.6 · 5.7 · 5.8 · 5.9 · 5.10 · 5.11 · 5.2 · 5.12 · 5.13 · 5.14 · 5.15 · 5.16 · 5.17 · 5.18 · 5.19 · 5.20 · 5.21 · 5.22
The lessons
- Density — Not how heavy something is, but how much of it is packed into the space it occupies. (5.1, 5.3, 5.4)
- Pressure, and Pressure in Liquids — Why a drawing pin works, why pressure at a point pushes every way at once, and why depth is the only thing that matters underwater. (5.5, 5.6, 5.7)
- Particles and Changes of State — What the particles are doing in each state — and why a boiling pan stays at 100 °C however hard you heat it. (5.8, 5.9, 5.10, 5.11)
- Specific Heat Capacity — Why the sand burns your feet and the sea is freezing on the same afternoon. (5.2, 5.12, 5.13, 5.14)
- Gas Pressure and Absolute Zero — Where the pressure of a gas actually comes from, and why the temperature scale has to start somewhere else. (5.15, 5.16, 5.17)
- The Kinetic Theory of Gases — One picture — fast random molecules bouncing off walls — that predicts everything a gas does. (5.18, 5.19, 5.20)
- The Gas Laws — Two equations that put numbers on everything the previous page explained. (5.21, 5.22)