Lava Lamp

Science Experiments for Class 5

Materials Required

  1. A plastic bottle.
  2. Water
  3. Food coloring
  4. Vegetable oil
  5. Fizz tablets like Alka-Seltzer


  1. Fill the bottle with a quarter full of water. Use the funnel to fill the water so that water don’t spill outside.
  2. Add vegetable oil in the quarter-filled water bottle until it is full.
  3. Now, wait for few minutes until the water and oil get separate.
  4. Add food coloring into the bottle.
  5. Now we can see that food coloring goes through oil and get mixed with water.
  6. Cut Fizz tablet into few smaller pieces and drop only one piece in the bottle. This will start reacting and appears like a lava lamp
  7. Whenever required drop another piece of the tablet to make a flow of bubbling in case the lava lamp stops.


The density of oil is lower than the density of water and both don’t mix well. The water and oil that is added in the bottle stay separately due to its density. Meanwhile, the food coloring goes through oil and mixes with water because the food coloring has the same density of water.

When you drop a piece of fizz tablet in the bottle, it releases carbon dioxide that appears as a small bubble and reaches the top by taking some of the water along with it. Now the interesting part is when the bubbles disappear on the top and the color falls back. Adding more tablet keeps the reaction for the longer time so that you can enjoy the lava lamp for an extended period of time.

Practise This Question

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