Intermixing of particles of different types of matter on their own is called diffusion
Experiment-3 : Take two beakers filled with water and put a drop of blue or red ink slowly along the sides of the first beaker and honey in the same way in the second beaker. Keep them undisturbed for some time.
Observation : The particles of ink quickly get distributed in water. As a result, colour of ink spreads throughout the water. On the other hand, particles of honey take a long time to. get distributed throughout the water.
Explanation : The particles of ink move rapidly due to weak forces of attraction between them. As a result, the particles of ink rapidly get into the spaces between the particles of water and hence quickly get evenly distributed in water. In contrast, the particles of honey move slowly due to strong forces of attraction between them. As a result, it takes a long time for the particles of honey to get into the spaces between the particles of water and to get evenly distributed throughout water
Conclusion : From above discussion we led to conclude that particles are continuously moving but their average speed at any particular temperature depends upon the forces of attraction
Stronger the forces of attraction, lower is the average speed, and thus lower will be the rate of diffusion.
*Particles of matter attract each other
The particles of matter have a force acting between them, which keeps these particles together. To illustrate this force of attraction, we perform the following experiments
Experiment-1: Take an iron nail, a piece of chalk and a rubber band. Try to break each one of them by hammering, cutting or stretching.
Observation & Explanation : It is most difficult to break the iron nail, followed by piece of chalk & then rubber band.
This is because, the particles of iron nail are held together by the strongest forces followed by the piece of chalk, while particles of rubber band are held together by weakest forces of attraction.
Conclusion : From above experiment, we conclude that “Particles of matter attract each other”. The strength of this force, however differs from one kind of matter to other
Experiment-2 : Try to break the stream of tap water with your fingers
Observation & Explanation : The stream can not be cut because particles of water attract each other strongly and hence tend to remain together
Conclusion : Particles of matter attract each other.