3 states of matter

• solids 


  Forces between particles are very strong. a solid cannot be compressed easily because the particles are closely packed. They have a fixed shape and volume.

  solids have a high density because their particles are closely packed.
• Liquids

  The particles are free to move over eachother. Forces between these particles are weaker than solids. A liquid cannot be compressed easily because The particles are closely packed. They have a fixed volume but their shape depends upon the container.

  Liquids also have high densities because the particles are closely packed.
• Gas

  The particles are moving very fast and in random directions. The forced between particles are weak. A gas can be squashed because there are large spaces Between the particles. Both their volume and shape depend on the container.

  gas has a low density because their particles are spread out.
• Melting

  When a solid is heated it gains more energy. This makes the particles move faster. At a certain temp the particles move fast enough to overcome the very small forces between the particles and are free to move
• Boiling

  When a liquid is heated it gains energy. If they are travelling fast enough towards the surface They can escape into the gas. If this happens normally its called evaporation. At a certain temp all of the particles have sufficient energy to overcome the weak forces of attraction that hold them together as liquid
• Cooling curve 


  When a gas condenses or a liquid freezes the temp remains the same because latent energy is released as the particles come together. when a solid melts or evaporates then the temp remains the same because all of the heat energy is required to break the bonds between particles.