Particles of matter intermix on their own with each other. They do so by getting into the spaces between the particles. This intermixing of particles of two different types of matter on their own is called diffusion. We also observe that on heating, diffusion becomes faster. Why does this happen?

NCERT Class 9th Science Ch 1 Matter in Our Surroundings



This is because while heating the temperature increases and the kinetic energy also increases ,which leads to faster intermix of particles (diffusion).