# Particles and atomic structure

Source: https://projectgcse.co.uk/chemistry/particles_and_atomic_structure

> We offer many resources for students revising for their GCSEs including: GCSE revision notes and practice questions, a GCSE bookshop, GCSE help and advice and the take a break section.

States of matter

- There are three states of matter: solid, liquid and gas.
- Solid: The particles are pact together in a regular structure. The particles vibrate.
- Liquid: The particles have no regular arrangement so they can flow but they are still quite closely pact together.
- Gas: The particles have no regular arrangement and they are not bonded together. They move in random motion.

Changing states

- solid to liquid = melting
- liquid to solid = freezing
- gas to liquid = condensing
- liquid to gas = evaporating
- solid to gas = subliming

Diffusion

- Diffusion is the movement of particles to fill the space they are in. This happens most rapidly with gases, slower with liquids and very slowly or not at all with solids.