With just water, a clear plastic bottle, vegetable oil, food coloring and some Alka-Selzter (or other tablets that fizz) you can create your own lava lamp on your kitchen counter.
Once you have everything you need to get started, here's what you'll need to do:
- Pour some water into the plastic bottle until it's about a quarter full.
- Pour some vegetable oil into the bottle until it's just about all the way full.
- Wait until the water and oil have clearly separated.
- Add around a dozen drops of your favorite color food coloring to the bottle.
- Observe the food coloring make its way through the oil and into the water, mixing.
- Cut an Alka-Selzter tablet into five or six smaller pieces and drop one of them into the bottle - things should start getting a little crazy, just like a real lava lamp.
- When the bubbling stops, add another piece of the Alka-Selzter tablet and enjoy!
If you're wondering what the science is behind this experiment, check this out: you know that oil and water don't mix very well (or at all), so the two separate from each other with the oil on top because it has a lower density than water. The food coloring is able to fall through the oil and mix with the water - key to this experiment! When you drop the Alka-Seltzer in, it releases small bubbles of carbon dioxide gas that rise to the top of the bottle, taking some of the colored water with it. The gas escapes when it reaches the top of the bottle and the colored water falls back to the bottom. To read more about the science involved, visit the Science Kids website.