1.3 explain the changes in arrangement, movement and energy of particles during these interconversions.

Solid: still; no energy; all particles touching

Add heat v / Remove heat ^

Liquid: Moving to fit space; some energy; all particles touching

Add heat v / Remove heat ^

Gas: Moving freely; lots of energy; particles not touching.

1.2 understand how the interconversions of solids, liquids and gases are achieved and recall the names used for these interconversions

Solid > Liquid
This process is called melting: you apply heat.

Liquid > Solid
This is freezing. You remove heat.

Liquid > Gas
Heat is added. The process is evaporation.

Gas > Liquid
Removed heat: condensing.



Diagrams are helpful to understand this concept. Be aware that you don't need to know the process between solid and gas/ gas and solid.

1.1 understand the arrangement, movement and energy of the particles in each of the three states of matter: solid, liquid and gas

Solids
As the picture shows, all the particles in a solid are touching. Another feature of a solid is that the particles aren't moving, the particles have no energy.

Liquids
Liquid particles are, like solids, all touching. The difference is that liquid particles are moving- they flow to fit the space- this means that they have some energy.

Gas
In gasses the particles aren't all touching; they are far apart. They move freely and have a high energy level.