• Brainly User
Diffusion refers to the process by which molecules intermingle as a result of their kinetic energy of random motion. Consider two containers of gas A and B separated by a partition. The molecules of both gases are in constant motion and make numerous collisions with the partition.
The spreading of the molecules of one substance from one place to another place is called diffusion. we can observe this when we lit a incense stick in a corner of the room and then the molecules of that incense stick move throughout the room and we can smell it.

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