States of Matter:

States of matter depend on the forces between particles.

Solids:

There are strong forces of attraction between particles. This means they are in a fixed, vibrating position in a regular arrangement.
Particles do not move from their positions. This means that all solids keep shape and volume and do not flow.
The hotter a solid becomes, the more they vibrate.
If you heat the solid, eventually it will melt into a liquid.

Liquids:

Some forces of attraction between particles. They’re free to move past each other but they stick together.
Don’t keep a definite shape and will take the shape of any container that they are placed into. They do keep the same volume.
Particles are constantly moving with random motion. The hotter the liquid is, the faster they move.
If you cool a liquid, it will freeze to become a solid. If you boil a liquid, it evaporates.

Gases:

Almost no forces of attraction between particles. They’re free to move, travelling in straight lines and only interacting when they collide.
Don’t keep a shape or volume and will always fill any container. When the particles bounce off the walls of a container, they exert pressure.
Particles move constantly with random motion. They hotter it gets, the faster they move. Pressure increases as heat increases.
If you cool a gas, it will condense into a liquid.

Limitations of the particle model:

How are atoms rearranged in chemical reactions?

When a substance changes matter, it’s a physical change since no new substances are made and it is reversible.
During a chemical reaction, bonds between atoms break and the atoms change places - the atoms you start off with (reactants) rearrange themselves to form different chemicals (products). These are hard to reverse.

	Created by Chloe Wood over 5 years ago

GCSE Chemistry Note on C1 Revision , created by Chloe Wood on 16/03/2021.