This animation uses a simple mathematical formula to generate the new positions of each particle. The beaker starts out with 100 molecules of gas at its bottom. The animation does not show the molecules of oxygen, nitrogen or carbon dioxide in the air. Unless the temperature is absolute zero, ie minus 273oC, the particles will all be moving about at random. Heating the gas will make the molecules move faster and cooling them will make them slow down. You can watch the molecules spread out; this is what actually happens in diffusion of gases. Eventually all the molecules will be so spread out there will be virtually none left, but since diffusion is a slow process, this will take a long time.

You can watch this animation for several hours until all the molecules have totally dispersed. Of course, if this was done in the open air with a slight breeze, it would blow all the chemical away in a few minutes. This is why you should pour chemicals out in the open air rather than in an enclosed space. DON’T pour petrol out in your garage or kitchen!

Refresh this page if you want to see the animation from the beginning again.