Enter our online science lab to find out more about states of matter. Interact with the activity and 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 about the states of matter in our study guide about temperature changes and energy.
What is happening when states of matter change?
The energy stored in the particles in a substance changes when the substance is heated. This can either make the temperature increase or change the state of the substance.
When the substance is heated the particles move faster and the temperature increases.
How to calculate the energy required to raise the temperature of a substance: multiply the specific heat capacity of the substance, the mass and required temperature change.
When the substance changes state there is no change in mass or temperature.
How to calculate the energy required to change the state of a substance: multiply the specific latent heat and mass of the substance.
Sublimation occurs when a solid changes state to a gas, or a gas to a solid.
Interactive activity - states of matter
Use this interactive states of matter diagram to see what happens to the particles inside substances when they are heated and change state. Select water, sodium chloride or iron and note how the melting and boiling points for these substances are different.
Test your understanding of the states of matter
How would you describe the change in the particle arrangement 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, how does the motion of the particles change?
As the temperature increases, the particles vibrate rapidly.
Which parts on the heating and cooling graph show a change of state?
Sections B and D show changes of state.
Where can I learn more about energy and states of matter?
The BBC Bitesize study guide about temperature changes and energy contains text, infographics and video to explain the concepts, plus more physics revision notes written to the Edexcel GCSE physics specification.
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 physics concepts. Listen to the series about energy for more on this topic.
Where can I test myself on states of matter and energy?
There are many ways to test yourself on Edexcel physics and sharpen your skills.
Interactive quiz about temperature changes and energy, with video feedback to aid your understanding.
Ten-question quiz on temperature changes and energy, with questions focused on states of matter.
Sample exam questions covering the particle model, with advice for multiple choice, descriptions and explanations, and extended writing.
Bitesize also has lots of general Edexcel physics test pages.
Exam practice quizzes based on past papers for GCSE physics.
Quick-fire quizzes with a new selection of GCSE physics questions each time you return.
Topic-based exam practice questions based on past papers, enabling you to choose the area of Edexcel GCSE physics revision you want to focus on.