Alka-Seltzer Lava Lamp Science Experiment
Decorate a clear cup with a Halloween monster face, then use vegetable oil, water, food coloring, and Alka-Seltzer to watch colored drops rise and sink.
Yield: 1 lava cup
Equipment
- 1 short, squat 9-ounce clear cup
- Measuring cups
- Tray
- Markers
Materials
- ¾ cup vegetable oil
- ¼ cup water
- A few drops liquid food coloring
- 1 Alka-Seltzer effervescent tablet broken into 4 pieces
- Googly eyes
- Craft glue for attaching the eyes
Instructions
- Decorate the outside of the cup with markers and googly eyes.
- Place the cup on a tray.
- Add the vegetable oil and water, leaving room at the top.
- Add a few drops of food coloring. Do not stir.
- Break one Alka-Seltzer tablet into four pieces and drop the pieces into the middle of the cup.
- Keep the cup uncovered and watch the colored drops rise and sink. The action lasted about 1–2 minutes in my test.
Notes
- Amounts are for one cup. Prepare each cup separately when making several.
- Use short, squat 9-ounce cups for the appearance shown in the finished photos.
- Vegetable oil is the only oil I tested.
- Additional Alka-Seltzer can restart the bubbling, but repeated additions made my mixture look more blended and oily.
- Keep uncovered throughout the reaction. This activity is for observing, not drinking. Use adult supervision.