Bromine boils at 59 ∘C59\,^\circ\mathrm{C}59∘C. A few drops of liquid bromine are placed in a sealed gas jar at 20 ∘C20\,^\circ\mathrm{C}20∘C. After some time, brown bromine gas is seen throughout the jar and some liquid bromine remains.
Which is the best explanation?
The bromine boils at room temperature because the jar is sealed
The bromine particles expand as they warm until they fill the jar
Bromine molecules split into atoms, which are light enough to fill the jar
Some particles escape from the liquid surface and then spread out randomly
84 exam-style questions on Edexcel GCSE Chemistry 3.1 States of matter, covering 3.1.1 The three states of matter and changes of state. Each one has a worked solution and a mark scheme showing where the marks go.