fbpx Skip to main content
Now open 7 days a week!

Virtual Science Fair

View All Activities

Density Rainbows

Have science fun as a family! Complete activities with parental supervision.

Materials:
  • 1 pack of food coloring
  • 5 different liquids*
  • 5 small cups or containers
  • 1 clear 8-oz cup or glass

* Try whatever you have on hand. Do not use chemicals or cleaning agents.

Procedure
  1. Add a small amount (3-4 tbsps) of each of the 5 liquids to the small cups with just one type of liquid in each cup.

  2. If needed, add food coloring to each of the liquids to give each liquid a distinct color. Otherwise, you can rely on the different colors of the liquids to create a natural rainbow.
    Note: most food coloring does not dye oil! Can you guess why?

  3. One at a time, pour each liquid into the clear 8-oz cup. Before pouring each liquid, predict where it will end up.

  4. Continue with the other liquids, one at a time. What are you noticing? Recommended pouring order: dish soap, honey, vegetable oil, water, rubbing alcohol.

  5. Stand back and admire your density rainbow! Be sure to take a picture to share in the Facebook comments on the Buffalo Museum of Science or Tifft Nature Preserve pages!

What’s it all about?

Density is a comparison between an object’s mass and its volume. Basically, it measures how much stuff is smushed into a given area.

Density = Mass/Volume

Based on this equation, if the weight (or mass) of something increased, but the volume stays the same, the density increases. If the mass decreases, but the volume stays the same, the density decreases.

Try It!

The same amount of two liquids can have different densities depending on how much matter is packed in to the liquid. Liquids with a higher density will sink below liquids that are less dense.

Temperature affects the density of a material. When things get cold, the atoms that make it up tend to squish together. Even liquids that are colder are more dense than those that are warmer.

More Great Virtual Science Fair Activities

  • All Ears!

    Animal ears have an inner part and an outer (pinna) part. The pinnae act as a funnel to collect and amplify sound and increase hearing abilities. Animals move their pinnae to help them locate sounds around them, especially to warn them of danger. Open Activity

  • Colorful Magical Milk

    What is soap made of and why does it work so well to keep our hands clean? Open Activity

  • A Penny Saved

    A penny saved is a penny earned, even a tarnished penny! So how do we put a little shine back into coins that have lost their luster?Open Activity

  • Constellation Viewer

    Discover the shapes that make up our favorite constellations in our next Virtual Science Fair activity! Bring the cosmos to the comfort of your living room with this DIY project.Open Activity

  • DIY Robot Hand

    We use our hands to grasp things, give fist bumps and communicate, but why are we able to use our hands in so many ways? See how our hands work on the inside with this easy prototype you can make at home.Open Activity