Enter our online science lab to find out more about changes of state. Interact with the activity and see what happens to the particles in substances when they are heated.
What are the three common states of matter?
Solid, liquid and gas are the three main states of matter. When a substance changes state, this is a physical change because no new substances are produced and the change is reversible.
The particles in solids, liquids and gases change arrangement and motion when a substance is heated or cooled. This is explained by the kinetic theory of matter.
Learn about solids, liquids and gases in our study guide explaining the three states of matter.
How do substances change state?
Changes of state happen when energy is transferred to a substance by heating it and the particles gain energy. During melting, some of the bonds between particles are broken. During evaporation or boiling, all the remaining bonds between particles are overcome.
Read more on this process in our study guide about change of state.
Interactive activity - changes of state
What type of change is a change of state? Interact with this activity to find out what happens to the particles inside materials when they are heated.
Choose between water, sodium chloride or iron, then observe and note how the melting and boiling points for these substances differ.
Test your understanding of the changing states of matter
In which state do the substances have the least energy?
Solid.
In which state is the average distance between the particles greatest?
Gas.
Between D and C on the graphs the substances are condensing. Is energy being given out to the surroundings or being taken in from the surroundings?
Energy is being transferred to the surroundings.
If a sample of sodium chloride has a temperature of 1300 °C, is it a solid, liquid or gas?
Liquid.
Where can I find out more about changes of state?
The BBC Bitesize guide to changes of state contains text, infographics and audio to explain the concepts, plus more chemistry revision notes written to the Edexcel GCSE chemistry specification. Alternatively, you can see all our guides about states of matter and mixtures.
To help your revision when you’re on the go, BBC Bitesize and BBC Sounds have developed the GCSE revision podcast series, covering a range of GCSE chemistry concepts. Check out the bonding, structure and properties series or go straight to the episode about states of matter.
Where can I test my knowledge of the changing states of matter?
There are many ways to test yourself and sharpen your skills.
Interactive quiz about the three states of matter, with video feedback to aid your understanding.
Ten-question quiz on states of matter, with questions focused on changes of state.
Sample exam questions covering states of matter and mixtures, with advice for multiple choice, structured questions, sentence completion and line matching.
Bitesize also has lots of general Edexcel chemistry test pages.
Exam practice quizzes based on past papers for GCSE chemistry.
Quick-fire quizzes with a new selection of GCSE chemistry questions each time you return.
Topic-based exam practice questions based on past papers, enabling you to choose the area of GCSE chemistry revision you want to focus on.
