Diffusion.

Evidence that matter is made of moving particles.

Particles move in all different types of motion, they collide and bounce against eachother eventually becoming evenly mixed, this is called, Diffusion.

This is especially seen in gases and liquids, but very difficult to take not of when in a solid form.

Diffusion is a consequence of the random motion of all atoms and molecules, diffusion of particular atoms and molecules always favours movement away from areas where those particles are more concentrated and also towards areas where those particles are less concentrated.

When the vapours that form scent, the scent of a flower are released they diffuse and spread throughout the air by themselves. This happens even if there is no breeze, and this is why we can smell things from far away. All matter can diffuse although in solids the process is much slower.

 By Joanne Tracey, Loreto College, Coleraine.