Pepper in Water

Water has a very high surface tension because of the strong hydrogen bonding between water molecules, which allows the pepper to float on top of the water. When a small amount of soap is added it forms a monolayer on the surface. The monolayer spreads away from the point of contact causing the pepper to move to the edges of the dish.

Camphor Particles

camphor sublimation

In this demo, camphor particles are placed in water. They sublime at room temperature which is why camphor’s odor permeates the room so quickly. The gas that forms around the particles propels the particles in random directions. Earwax contains a large percentage of long chain fatty acids which form a monolayer in water, thus ceasing the motion of the camphor particles.