Raven class have been conducting science experiments. The two videos below are fascinating to watch.
The attached chemistry videos use potassium permanganate to visually demonstrate the process of diffusion. Diffusion is the random movement of particles from an area of high concentration to an area of low concentration until equilibrium (evenly spaced particles) is reached (think of a room air freshener). It is a passive process in that it does not require energy, using only the random motion of the particles.