Today’s STEAM Activity is making Lava Lamps! Growing up I had a green lava lamp in my room. It was already considered a “retro” toy back then, but I absolutely loved it! It was mesmerizing and relaxing for me to stare at and I loved the soft glow it made while I studied in my room at night. I was pleasantly surprised by how much these STEAM lava lamps look like the lava lamp I had growing up.
My kids have never seen a lava lamp before, so activity really blew their minds. They were amazed and fascinated by the moving colors. I’ll teach you how to do this easy activity at home today! I bet you already have everything you need.
- Small clear cup or jar
- Food coloring
- Alka Seltzer tablet
- Fill your jar 2/3 full with oil (this is why you want a small jar)
2. Add water until there is about 1″ of space at the top of the jar
3. Add 5-10 drops of food coloring
4. Break your Alka Seltzer tab into 4 pieces. Start dropping the pieces into the jar one at a time, watching the bubbles grow with each addition. The food coloring will eventually get mixed into the water by the turbulence from the bubbles.
5. Enjoy watching the slow moving bubbles. Afters the bubbles stop, let the oil and water separate again and you can add another Alka Seltzer tab and start the lava lamp show all over again!
*Note: You can repeat this experiment over and over using the same jar of oil and water. You do not have to dump and start again each time you want to do it. Just let the Alka Seltzer tab completely dissolve and all the bubbles stop, and then it’s ready to go again. We are saving our jars of oil and water so we can do this experiment whenever my kids want to see it again.
Remember when you are finally ready to dump the lava lamp contents, don’t dump it down your drain! Please responsibly dispose of your oil, check your local waste disposal guidelines on how to properly discard oil.
STEAM CONCEPTS LEARNED:
- Science: Oil and water don’t mix. Water is polar and oil is non-polar and hydrphobic, meaning it repels water. Oil is less dense than water, so when they are combined they immediately separate and their difference in densities makes the oil float on top of the water. You see this separation at the start of the experiment when you add water to the oil in the the jar, and also when you add the food coloring.
The food coloring is water soluble so it only mixes with the water and not the oil. When you add it to the jar, you will see it sink down below the oil and sit on top of the water until the bubbles from the Alka Seltzer tab mix it into the water.
As the Alka Seltzer tab dissolves in the water it releases carbon dioxide bubbles. These bubbles are lighter than both liquids so they push from the bottom of the jar towards the top, taking blobs of water with them through the oil. The carbon dioxide bubbles break when they hit the surface, then the water falls back down to the bottom of the jar due to its heavier density.
I hope you try this groovy experiment with your kids! My kids absolutely loved this activity! Remember, don’t throw the oil away. Save it in the jar and you can repeat this over and over, as long as you have Alka Seltzer tabs!