The idea came from this blog via Pinterest. To make a homemade lava lamp, you need cooking oil, water, food coloring, alka seltzer, and a bottle (we used glass Snapple bottles).
First, we filled 2 bottles (1 for each girl) 3/4 full with cooking oil.
Then, we added the water until the bottle was close to full.
The girls chose their colors and added in 10 drops of food coloring.
We watched the food coloring rain down through the oil and into the water.
Then came the really fun part! I gave each girl an alka seltzer tablet, which they broke into 4 pieces. They put one piece in the bottle at a time. It was SO much fun to watch the bubbles go crazy in the bottle!
The girls shook their bottles up, and they were pretty excited by the thousands of tiny bubbles.
They wanted to keep adding alka seltzer, and they ended up putting 3 tablets into each bottle.
They added in different colors into their bottles to see what would happen. O(6) said "This is awesome!"
E(2) LOVES her lava lamp and wanted to carry it with her everywhere. They are looking forward to adding more alka seltzer to their bottles when we get home from vacation :)