Science at home can be simple and fun! A rainbow water tower is a colorful way to understand water density. Grab a few household items and experiment.
Density is the mass of an object compared to its volume (density = mass/volume). One example of mass over volume is comparing a can of diet coke to regular coke. Yes, both cokes are in 12-ounce cans. However, if placed in water, the can of diet coke will float while the regular coke sinks. Why? The regular can of coke contains sugar and has a higher density.
Gather the materials below and create a rainbow water tower. Once you’re done, we have more STEM activities you can do in 20 minutes or less.
Materials List
- 6 clear cups
- 3 cups warm water
- Red, green, yellow, blue liquid food coloring
- 5 tablespoons white cane sugar
- 7 craft sticks for mixing
- 1 narrow tall clear container
- 5 ml dropper
What to Expect
The rainbow water tower has six colors. You will find adding sugar to the water increases its density. Purple has the most sugar and will be the densest, while red will be the lightest allowing it to stay on top.
Color Amount of Sugar Food Color
Red No sugar 2 drops red
Orange 1 teaspoon 1 drop red, 1 drop yellow
Yellow 2 teaspoons 2 drops yellow
Green 3 teaspoons 2 drops green
Blue 4 teaspoons 2 drops blue
Purple 5 teaspoons 1 drop blue, 1 drop red
Rainbow Water Tower Directions
- Add ½ cup of warm water to each cup.
- Place the designated amount of sugar in each cup. Use a craft stick to mix until dissolved.
- Add food coloring to each cup. Use a clean craft stick to mix each color.
- Add 5 full drops of purple water to the clear narrow container.
- Next, use the dropper to slowly release blue water drops close to the wall of the purple container . (See the photo)
- Do the same with green, yellow, orange, and red – in this order.
- Carefully hold the full container up to a window to see the rainbow water tower.
