Diffusion is the gradual movement of particles from places where there are lots of them to places where there are fewer of them.
In the end they are evenly spaced.
Diffusion is the PASSIVE MOVEMENT of particles from an area of HIGH CONCENTRATION to an area of LOW CONCENTRATION.
Diffusion occurs in liquids and gases.
The particles in these substances are free to move about randomly.
DistIt is simple when different gases diffuse through each other.