Welcome to the next installment of our Summer of Science activity series!

We’re issuing a challenge to make your family’s summer the best one yet – by making it a Summer of Science. To help make it a science-filled summer, we’ll post a new science activity on our blog, from now until August. Give each activity we post a try and take a photo of what you create – or whatever you discover in the process! For each photo you post and tag #CuriOdysseySummerSci on Flickr or Twitter, you’ll be entered into a drawing for CuriOdyssey passes.

Using knowledge of liquid density, you can easily “stack” several liquids on top of each other! Use food coloring to make a cornucopia of colors in this Rainbow Density Column activity.

You’ll need:
Liquids of different densities: honey, corn syrup, dish soap, water, vegetable oil, rubbing alcohol
Graduated cylinder or tall glass or jar
Pipets (medicine droppers)
Food coloring

What to do:
– Pour an inch of honey into the bottom of the cylinder or glass.
– Use food coloring to color a little bit of corn syrup. Slowly pour an inch of the corn syrup on top of the honey.
– Color some liquid dish soap and carefully add an inch on top of the corn syrup.
– Next, use a pipet to add an inch of colored water on top of the dish soap.
– You won’t be able to color the vegetable oil, because food coloring is water-based and water and oil don’t mix! Now add an inch of oil on top of the water.
– Finish it off with an inch of colored rubbing alcohol. Voila – a beautiful rainbow of stacked liquids!

What’s happening here?
Each of the liquids you used had a different density. You added them to the cylinder in order of most dense (honey) to least dense (rubbing alcohol). Because each new liquid was less dense than the one before it, it floated on top instead of mixing together.

Tag your photos on Flickr or Twitter with #CuriOdysseySummerSci and you’ll be entered into a drawing for a chance to win CuriOdyssey passes. The more photos you post, the more times you’ll be entered.

Check back soon for the next Summer of Science activity!