1. What makes a material a solid, liquid or gas?

2. 1. Let’s think back! What do you already know about particles?
How do you think the particles are arranged in solids, liquids and gases?
How does what you have observed about the appearance and behaviour of solids, liquids and gases link to what you know about particles?
Can you do three group drawings to show how you think the particles are arranged in a solid, a liquid and a gas?

3. 2. Falling marbles
What did you notice? Does this fit in with your ideas about materials?
What evidence does this give you to support your ideas about particles?
What do you think is happening to the particles of the material as the marbles fall through it?
How do you think this is this different in solids, liquids and gases?

4. 3. Plenary – virtual particles
How did the simulation help you explain the differences between solids, liquids and gases?
How can looking at the arrangement and behaviour of particles help you identify a solid, liquid or gas?
Do these ideas fit in with what you think about how materials behave?
What evidence supports your ideas? Are there any counter-arguments to what you think?