A substance can exist as a solid, a liquid or a gas.
Explain, in terms of the arrangement and movement of particles, why the density of a substance is different in each state, and why its mass stays the same when it changes from one state to another.
87 exam-style questions on Edexcel GCSE Physics 14.1 Density and states of matter, covering 14.1.1 Kinetic theory and states of matter, 14.1.2 Density, and 14.1.3 Density and changes of state. Each one has a worked solution and a mark scheme showing where the marks go.