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Krum Independent School District

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Week 4: Lava Lamp

We are fascinated by how some liquids mix, or not! This lava lamp experiment is a fun way to see it happening! 

Lava Lamp


  • Jar or clear container
  • Water
  • Vegetable oil
  • Food coloring
  • Alka Seltzer tablets, broken into fourths


  1. Fill the bottom of the jar about ⅛ of the way with water
  2. Fill the rest of the jar with vegetable oil
  3. Add in as many drops of food coloring as you want
  4. Drop-in a piece of the Alka Seltzer tablet.
  5. Keep adding tablets to watch the science continue! 

Krum ISD Summer Science Week 4:Lava Lamp from Krum ISD on Vimeo.

Why It Works: 

Due to it’s lower density, all the oil floats above the water. Food coloring is heavier than oil, and so it sinks to the bottom. The tablet dissolves when added to the jar and releases carbon dioxide, which is lighter than water. It floats to the surface, and brings a little bit of the colored water with it! Once the gas reaches the surface and escapes, the colored water sinks back to the bottom of the jar. 

This experiment and the science behind it located on Beyond the Playroom