Find out all you need to know about states of matter here in our online science lab. The interactive activity lets you see what happens when different substances change state.
How many states of matter are there?
There are three main states of matter: solid, liquid and gas. 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 down. This is explained by the kinetic theory of matter.
Read more in our study guide about the density of solids, liquids and gases.
States of matter – interactive activity
Use this interactive activity to see what happens to the particles inside substances when they are heated and when they change state. Choose between water, sodium chloride and iron then note how the melting and boiling points for these substances differ.
Test your understanding of the states of matter
How would you describe the change in the particle arrangement and motion when the iron particles reach the melting point?
The particles are no longer vibrating in fixed positions. They start to slip and slide over each other.
What is the boiling point of sodium chloride?
1465 °C
When solid sodium chloride is being heated, what happens to the motion of the particles as they are heated?
As the temperature increases, the particles vibrate rapidly.
Which parts on the graph show a change of state?
Sections B and D show changes of state.
Where can I learn more about states of matter and kinetic theory?
Take a look at our study guide about the density of solids, liquids and gases, which explains the concepts with infographics and tables. Or explore the kinetic theory topic page which has more physics revision notes written to the CCEA Double Award GCSE Combined Science specification.
For on-the-go revision, BBC Bitesize and BBC Sounds have produced a series of GCSE revision podcasts, covering a range of GCSE physics themes. Listen to the energy series for more on this topic.
Where can I test myself on kinetic theory and states of matter?
BBC Bitesize has lots of ways to test your knowledge of this specific topic plus more general CCEA Double Award Combined Science tests, including:
A ten-question quiz on measuring density, with questions about states of matter.
Exam-style questions based on past papers for GCSE combined science.
Quick-fire quizzes with a fresh selection of GCSE combined science questions every time you return.
Topic-based practice questions based on past exam papers. This quiz lets you choose the GCSE combined science topics you most want to focus on.
