Leprechaun Lava Lamps

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Ever wonder how those lucky Leprechauns stay so relaxed while you try to find their pot of gold? We investigated it and decided that they must have their own special lava lamps!

Leprechaun Lava Lamps

Materials:Materials for Leprechaun Lava Lamps

  • Clean, plastic soda bottle, glass, or jar
  • Vegetable oil
  • Food coloring
  • Alka-Seltzer tablet or Fizzy Tablets
  • Flashlight
  • Water


  1. Fill the bottle 9/10ths full with vegetable oil.
  2. Fill the rest of the bottle with water (not overflowing).
  3. Add 5-10 drops of food coloring. Be sure to make the water fairly dark in color. Notice that the food coloring only colors the water and not the oil.
  4. Drop the Alka-Seltzer table in. Watch what happens. When the bubbling stops, add another chunk of Alka-Seltzer. It’s just like a lava lamp!
  5. If you want to make it even more cool put your bottle on top of a flashlight and turn the room lights off.


How does it work?

Oil and water do not mix, right? Did you confirm that? The molecules of water do not like to mix with the molecules of oil. Even if you try to shake up the bottle the oil doesn’t mix with the water. It only forms lots of smaller drops. Also, food coloring only mixes with water, and does not color the oil.

When you pour the water into the bottle with the oil, the water sinks to the bottom and the oil floats to the top. Oil floats on the surface because water is heavier, or more dense, than the oil.

The Alka-Seltzer tablet reacts with the water to make tiny bubbles of carbon dioxide gas. These bubbles attach themselves to the globs of colored water and cause them to float to the surface. When the bubbles pop, the color blobs sink back to the bottom of the bottle.

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