Create a colorful, bubbling lava lamp using simple household ingredients. You will learn about liquid density and chemical reactions as you watch colorful bubbles dance in the jar.

Materials

• clear container or jar (16 oz)
• vegetable oil (approx. 1 cup)
• water (approx. 1 cup)
• food coloring (8-10 drops)
• Alka-Seltzer tablets (2-3 tablets)

Safety

• Adult supervision is required to ensure Alka-Seltzer tablets are not ingested.
• Be careful not to spill oil on the floor as it can be very slippery.
• Do not eat or drink any materials used in this project.
• Protect work surface. Materials may stain clothing.
• Adult supervision required for children under 8.

Steps

1. Remove the lid from your clear container.
2. Fill the container about one-third of the way with vegetable oil.
3. Fill the remaining space with water, leaving a small gap at the top to prevent the mixture from overflowing when it bubbles.
4. Wait a few minutes for the oil and water to completely separate into two distinct layers.
5. Add 8 to 10 drops of your chosen food coloring into the jar. The drops will pass through the oil and mix with the water layer.
6. Break the Alka-Seltzer tablets into small pieces.
7. Drop the tablet pieces into the jar one by one and watch the colorful fizzy bubbles rise and fall like a lava lamp.