If you have spent some time exploring colors (and color mixing) with your kids, this activity is a great way to take that learning a step further. It is simple to set up, easy for kids to do on their own with some guidance, and gives them an introduction to density!
It is fun to have kids guess what will happen if you mix the following colored liquids together before you start! Before mixing our liquids we learned about a new word: Density! My preschoolers spent some time discussing how some of the liquids moved slowly when you turn their containers upside down (like the honey and corn syrup) while others move quickly (like the vegetable oil and rubbing alcohol). We also had a conversation about the terms thick and thin.
What You’ll Need
Honey (a darker color will look slightly orange)
Light corn syrup (with red food coloring)
Blue dish soap
Water or rubbing alcohol (with green food coloring)
Glass jar with a lid
Optional: Rainbow Density Jar label
Step One: Have your child pour the liquids into your jar, one at a time. Add them to your jar in the order listed above. This is something little kids should be able to do on their own. It helps with fine motor skills, and is an opportunity to work on measurement if you use any measuring cups to help with pouring. In my group, we focused on fine motor skills (squeezing) for the more dense liquids. We worked on measuring with the oil and rubbing alcohol to prevent pouring too much too fast or spilling.
It is so fun to watch the kids' excitement as the colors do not mix, but instead, form layers!
Step Two: Once you have all of the liquids added to your jar, put the lid on it. You can add a cute label to the jar and can keep it around for awhile.
Step Three:Gently mix it up. Instead of shaking it we just turned the jar slowly upside down a few times. If you shake it up too much it will look like this:
It will probably never separate back into layers if it you shake it that much. You want it to look closer to this:
Now the kids can watch as the layers re-separate back into a rainbow right before their eyes!