My kids had a great deal of fun this past week with an old plastic bottle, some vegetable oil, water, food coloring and some antacid tables. The bottle was filled 1/4 of the way full with water, and 3/4 of the way with oil. A few drops of food coloring were added and shaken until they mixed with the water. Then they added an antacid tablet. It sank down into the layer of water and started making colorful bubbles of colored water and carbon dioxide rising to the surface.
Next we decided to heat the water up, so my husband set up a sort of double boiler placing the bottle of water on a steaming rack inside boiling water. We could watch bubbles rising as the water in the jar started to boil – the bubbles were generally clear ones, with the food coloring remaining at the bottom.
When we removed the bottle from the heat the kids wanted to try adding another antacid tablet. They had a bit of a harder time getting the antacid tablet to sink to the bottom in the warm bottle but they were delighted with the huge bubbles erupting when it did.
We let them play with the lava lamp adding tablet after tablet. They turned the lights off and shone a small book lamp through the water. At some point they started singing campfire songs sitting around the glowing liquid.
I’m linking this page up with the outside the toy box summer fun series… click here to go see other ideas for what to do with a plastic bottle.