These colorful lava lamps are not just fun to look at, but they are also bursting with a chemical reaction that makes it all possible.
So, how does it work?
Well we know one thing, oil and water do not mix. You will even notice that the food coloring only mixes with the water, not the oil. Since water is heavier, all of it sinks to the bottom while the oil floats to the surface. The Alka Seltzer tablet reacts with the water to create tiny bubbles of carbon dioxide gas. These bubbles attach themselves to the blobs of colored water and cause them to float to the surface. When the bubbles pop, the blobs of colored water sink back down, bursting with color.
Source: Steve Spangler Science