Lava Lamps
Oil and water have different densities. Water is denser, so it sinks below the oil. Oils’ long chain molecules don’t like to mix with water’s tiny, polar molecules. When Alka Seltzer tablets dissolve in water, it reacts to make bubbles of carbon dioxide gas. The gas bubbles rise up because it is the lightest of all the parts. Along the way, it captures some of the colored water to bring to the surface of the oil. Without the light air, the water falls again. When all the gas has escaped, the water and oil separate into two layers again.
WARNINGS & SAFETY
Do not drink any of the fluids! Do not close the water bottle when there is active fizzing, as pressure can build up inside.
