Particles vibrate in fixed position; fixed shape and volume
Liquid:
Weaker intermolecular forces than solids
No fixed arrangement; particles can move and slide over each other
Particles slide; fixed volume
Gas:
Almost no intermolecular forces
Particles far apart and move quickly
Random movement; no fixed shape or volume
When a solid is heated, the particles gain sufficient energy to overcome the strong intermolecular forces.
When a solid is heated particles eventually can slide over each other in a more randommotion- solid expands until the structure is broken at melting point.
When a liquid is heated to its b.p, the particles overcome the relatively weaker intermolecular force to escape the liquids surface and move around in continuousrapid motion – the liquid has boiled
In the vapor, the particles move in rapidrandom motion. This movement is due to the collision of vapor particles with air particles.
When gaseous particles are heated in a closed environment, the increase in kinetic energy causes increased collisions with other particles as well as the walls of the container- pressure increases.