Understanding Diffusion

Sir, what is diffusion exactly? Imagine I open a bottle of

perfume here near the teacher's table. After a few seconds, students at the

back start smelling it. How did it reach there? Because the air

carried it? Yes, through the movement of perfume particles in air.

This spreading is called diffusion. So diffusion means smell spreading? Smell spreading is

one example. In general, diffusion is the movement of particles from a region

of higher concentration to a region of lower concentration until they spread evenly.

Higher concentration means where there are more particles? Exactly! Near the perfume