Homemade Lava Lamp

We made lava lamps for our Wednesday learning playdate. I bought Steve Spangler's Secret Science book at an NAEYC conference for work a few years ago. His presentation at the conference was amazing. Boogs and I have used his website for project/experiment ideas and have purchased many things from his catalog and website.

On the very first page of Secret Science, it says "Don't try this at home... Try it at a friend's home!" I laughed as I showed that statement to my friend C, whose house is where we do all of our messy playdates. The lava lamp experiment is very simple. You need a bottle with a cap, vegetable oil, food coloring, Alka Seltzer, and water.

It was a rainy day, so the kids kept themselves occupied inside the house while we gathered the supplies.

B cutting up Alka Seltzer tablets into 8 pieces.

Fill the bottle 3/4 full of oil.

Fill the rest of the bottle with water.

We let the water settle while we discussed what was happening. One kiddo thought the water sank while another kiddo thought the water floated. We talked about the oil spill in the Gulf of Mexico and the kids figured out that oil floats on water.

Next step, add food coloring. 

They each started out adding a few drops.

But eventually, they squeezed every last drop out of all four bottles of food coloring.

Watching the color sink. The food coloring only mixes with water.

Adding the Alka Seltzer tablet. The colored bubbles danced up to the top of the bottle then floated down again. The carbon dioxide bubbles attach to the color blobs and float the color to the surface. When the bubbles pop, the color blobs sink.

While C and I were cleaning up the mess, Boogs and B brought over this pan and said, "Look we made oil for the car. Can we go put it in?"

We left the bottles alone for a bit to settle. 

This was a fun and quick experiment. I can't wait to figure out what we are going to do next week. Any suggestions?

(I forgot to take my camera with me so these fuzzy photos were all taken with my camera phone.)