AQA GCSE FOUNDATION Chemistry: States of Matter

AQA GCSE Foundation Chemistry: States of Matter

The Particle Theory

The particle theory explains the different states of matter: solids, liquids, and gases. Here's the breakdown:

• All matter is made up of tiny particles
• The particles are constantly moving
• The particles have spaces between them

The arrangement and movement of these particles determine the state of matter.

Solids

• Particles are closely packed together.
• Particles vibrate in fixed positions.
• Strong forces of attraction hold particles together.
• Definite shape and volume.

Think of it like this: Imagine a tightly packed crowd of people at a concert. They are close together and can only vibrate slightly, much like the particles in a solid.

Liquids

• Particles are close together, but can move around.
• Weaker forces of attraction than solids.
• Take the shape of their container, but have a fixed volume.

Think of it like this: Imagine a group of friends at a party. They are still close together, but can move around freely. They are like the particles in a liquid.

Gases

• Particles are far apart.
• Move freely and randomly.
• Very weak forces of attraction between particles.
• Take the shape and volume of their container.

Think of it like this: Imagine a swarm of bees flying around in a room. They are spread out, moving freely in all directions, just like the particles in a gas.

Changing States

You can change the state of matter by adding or removing heat energy. This energy affects the movement of the particles:

• Heating increases the energy of particles, causing them to move faster and spread further apart.
• Cooling decreases the energy of particles, causing them to move slower and come closer together.

Think of it like this: Imagine putting ice cubes (solid) in a hot pan. The ice cubes will melt into liquid water. If you continue heating the water, it will eventually boil and turn into water vapor (gas).

Key Points

• The particle theory explains the different states of matter.
• The arrangement and movement of particles determine the state of matter.
• Heat energy affects the movement of particles, which can cause changes in state.