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

Firstly, it is important to understand that physical changes dont change the particles, just their arrangement or their energy.

The Processes

Solid to liquid - when a solid is heated, its particles gain more energy, this makes the particles vibrate more which weakens the forces that hold a solid together, this makes the solid expand. At a certain temperature, known as 'boiling point' (different for different substances), the particles have enough energy to break free from their positions.

Liquid to gas - when a liquid is heated, the particles gain more energy, this energy makes the particles move faster which weakens and BREAKS the bonds holding the liquid together. At a certain temperature (different for different substances), the particles have enough energy to break their bonds.

NOTE: for our exams, we do not need to know sublimation or deposition (: