🌈 Craft Your Rainbow with Sugar – A Fun Density Challenge!

Did you know you can effectively demonstrate density with just food coloring, sugar, and water! Don’t believe me? This rainbow in a jar experiment with sugar allows you to show kids how the more dense a liquid (colored for visual purposes only), the heavier it is and it will sink. This rainbow in a jar is quick, easy, and cheap to try. Use this rainbow jar experiment in the spring or as part of a science lesson on density for kids. No matter how you use it, this density experiment makes an impression with pre-k, kindergarten, first grade, 2nd grade, and 3rd graders too.

Rainbow in a jar experiment with sugar

Did you know you can effectively demonstrate the concept of density using just a few household items like food coloring, sugar, and water? It’s true! If you’re looking for a fun and educational activity, check out this amazing rainbow in a jar experiment. Not only is it visually stunning, but it’s also an engaging way to teach kids about density!

Wondering how it works? When you add varying amounts of sugar to different layers of water (all colored for extra fun and visual appeal), you create liquids of different densities. The more sugar you add, the denser the liquid becomes. As a result, the colored water with higher density will sink below the lighter, less dense layers, creating a beautiful rainbow effect in your jar!

This experiment is quick, easy, and budget-friendly, making it perfect for parents, teachers, and anyone looking to bring some science into their day. It’s a fantastic hands-on project for springtime or as part of a classroom discussion about the principles of density. Whether you’re working with pre-k, kindergarten, 1st grade, 2nd grade, or even 3rd grade students, this density experiment is sure to make a memorable impression.

So gather your materials and get ready to create your very own rainbow in a jar! It’s a colorful way to explore science and a great opportunity for kids to learn about how different substances interact. Who knew that a little food coloring and sugar could lead to so much fun and learning?

We have lots more kindergarten science experiments including a summer density tower and this easy capillary action rainbow experiment

rainbow in a jar

This simple density jar experiment only requires a few simple ingredients:

water
sugar
food coloring
pipette or science syringe (handy for laytering)
heat source (warm water absorbs sugar better)
tall narrow glass container for layering

rainbow jar experiment

While this is a super simple density experiment for kids, it does require you to follow the directly exactly or you will just have sweet, colored water.

Combine the following each in a seperate cup:

no sugar, & red food coloring
1 Tablespoon sugar & yellow food coloring
2 Tablespoons sugar & green food coloring
3 Tablespoons sugar & blue food coloring

Note: You only need a few drops of food coloring per cup.

Now add 3 ounces HOT water per container and stir until the sugar has dissolved.

rainbow jar

Now it’s time to make the rainbow density tower out of sugar water. Make sure you layer the liquids slowly. Start by pouring the blue water in your layering container. It has the most sugar and therefore is the most dense – it will settle at the bottom of the rainbow.

Density Experiment

For the next color you will want to use a syringe or pipette to not stir the layers, but instead stack them to make a pretty rainbow. Carefully and slowly add the green sugar water to the container. I suggest running the water down the inside of the glass. As the green water is added you will notice that it does not mix with the blue water but rather sits on top of it!

rainbow density experiment

Now slowly begin adding the yellow water to the container using the same methodology with the pipette, going SLOWLY and runnig it down the side of the conater.

rainbow in a jar experiment

Once all of the yellow water is added repeat this process with the red water. The red water has no sugar in it (fewer molecules mixed in the water) so it is the least dense. Unless you stir, it wil sit on the top of the other, denser colors of sugar water.

rainbow in a jar science experiment

So what is density anyway. Density helps us predict if something will sink or float. The more dense an object is, the more the molecules are packed together making it heaviest for it’s size.

Extension Activity: Look up swimming in the Great Salt Lake in Utah or Dead Sea in Israel. These bodies of water are even saltier than ocean water.

So would they be more or less dense than the Atlantic Ocean?
Is the Pacific Ocean more or less dense than a lake or swimming pool?

Now see if your parent can help you google swimming in the Great Salt Lake or the Dead Sea. Peopl float on the top of the water. The fluid is dense people are pushed to the top. That’s because the water is denser than pool water, due to the high salt concentration.