Contained Chaos: Fireworks in a Bottle
Okay, so you won’t be actually shooting off fireworks with this craft, but the way the food coloring shoots to the bottom of your cup, it will look like upside down fireworks and your kids will be amazed.
- 2 glasses (at least one of them must be clear)
- Warm water
- Food coloring
Start by filling up the clear glass with warm water. You want to make sure it’s about 3/4 to 4/5 full. Then fill your second glass with oil (we just used canola oil), but only use a few tablespoons. Now let your kiddo pick out their favorite color of food coloring and add it to the cup of oil. Mix it up with a fork to break up the oil and food coloring particles.
Now let your little one watch while you pour the oil mixture into the cup of water. Ask them what happens. At first, not much will happen. The colored oil will sit on top of the water for a little bit.
But before long, the food coloring will make its way down into the water and start shooting to the bottom just like a firework! If you are doing this with an older child, you can explain to them the science behind this: water and oil don’t mix because water is made of polar molecules and oil is made of non polar molecules. And because water is more dense than oil, the oil sits on top of the water. However, the food coloring, which is mixed with the oil, has a water base. This means that it is polar so it can mix with water, however the solution is just ever so more dense than water itself. So the fireworks your child is seeing is really the food coloring breaking free of the oil, sinking through the water and eventually dissolving into it. Sometimes you will even see a few of the colored droplets shoot to the top of the cup after they have sunk. Why? Possibly the food coloring pulled a bit of oil with it when it sank and then you are watching the oil breaking free of the food coloring once it hits the bottom, making its way back up to rejoin with all the other oil particles.
As everything settles, you will have a colored cup of water with a thin layer of uncolored oil sitting atop of it. As if you had mixed the coloring with the water and then poured in uncolored oil. Kind of neat how science works, right? If my College Chemistry class was this interesting, I might have actually stayed in the science field!