Revision - year 7

Introduction to the Particle Theory

What you should be able to remember from last yeat

​(Hopefully)

• Substances are made up of particles

• Particles explain the properties and behaviour of solids, liquids and gases (states of matter)

States of matter

​For example:

Matter can move between the different states, particularly if it is heated or cooled.

When a substance goes from a gas to a liquid, it is called condensation

Multiple Choice

When a substance goes from a solid straight to a gas, it is called what?

• sublimation
• melting
• there's no such thing

• vaporization

​Particle diagrams

We can use diagrams to show the behaviour of particles in solids, liquids and gases.

For example: particles in a solid look like
this - close together and vibrating slightly

Draw

Draw what the particles in a gas look like

States of matter

Solids - Particles are closely packed in a fixed position but vibrate on place. Solids have a definite shape and volume.

Liquids - Particles are closely packed but can move past each other, allowing liquids to flow and take the shape of their container. They have a definite volume.

Gases - particles are far apart and move freely, filling the volume of the container that they are in. They do not have a definite shape or volume.

Poll

I remember this

• I know it well

• I know a bit

• I don't know much

• I have never seen this before

Word Cloud

We use our understanding of particles to help separate substances. Name a method of separating substances (for example, gravity separation - used for gold panning)

​Physical and chemical properties describe different things about matter

Physical and chemical properties