Solid iodine is warmed and turns directly into purple iodine vapour. The vapour is then cooled on a cold surface and solid iodine forms again. Which statement about these two changes is correct?
Both are chemical changes because a new substance has been formed
The first is a chemical change and the second is a physical change
Both are physical changes because the mass of the iodine increases
Both are physical changes because the iodine recovers its properties
40 exam-style questions on AQA GCSE Physics 3.1 Changes of state and the particle model, covering 3.1.1 Density of materials and 3.1.2 Changes of state. Each one has a worked solution and a mark scheme showing where the marks go.