The atomic model and the physical properties of matter.

Transitions of physical states

1.Sublimation 2.Resublimation 3.Condensation 4.Vaporisation 5.Fusion 6.Solidification

In solid state, molecules are without motion and in contact with each other, in liquid state they are in contact , but moving, in gaseous state they move rapidly and are dissociated.

Evaporation of a substance

At low temperatures, the molecules of a liquid substance may escape from the liquid to the air, that is why the air may be humid!

Smell

At low temperatures, the molecules of a solid substance may escape from the solid, that is the reason for odours!

Thermal diffusion

Because of thermal motion, molecules of different gases (or liquids) may mix together. That is the reason for diffusion.!

Pressure of gases

Pressure of a gas on a separation wall is due to strokes of molecules against the wall. That's why an air-emptied plastic bottle is crushed by the molecules of outer air.

Thermal expansion

Rising the temperature of a solid leads to more vibration of molecules. That is why the solid expands.