Tuesday, June 17, 2014

Easy Science Experiments for Kids: Discover Liquid Density

So far in our easy science activities for kids series we have learned how clouds work and how static electricity works.

Today, we will show you an extremely simple way to learn about liquid density.

Simple Liquid Density Experiment


  • 3 separate clear containers (we used mason jars)
  • 1 large container
  • A heavy liquid (could be honey, corn syrup, or molasses like we used)
  • Water
  • Vegetable oil
  • Food coloring (optional)

Pour about a cup of each of the liquids into the three individual containers. Use less if you have smaller containers. We decided to dye our water blue, but it ended up blending in with the dark color of our molasses. I recommend using a brighter color like red or yellow if your bottom layer is as dark.

Have the children guess what liquid will rise to the top. Record the guesses on your density sheet.

Pour all the liquids into a single jar and wait for them to separate. It shouldn’t take more than a minute or so. See if your guesses were right, or if you were wrong. Talk about what makes a liquid denser than its fellow liquids.

The Science of Density

Different liquids have different densities based on their weight. A cup of oil, for example, will weigh a little less than a cup of syrup. Liquids with the highest density will sink to the bottom of a cup, while liquids with a lower density will rise to the top. In general, density is how many particles are inside each liquid. In an equation, density equals mass divided by volume. When the mass of an object increases but the volume stays the same, the density increases.

Take Density a Little Further

You can take this experiment one step further by dropping a variety of household objects of various weights into the liquids. Let your children guess where they think the objects will settle. Use objects like:
  • Coins
  • Plastic beads
  • Bottle caps
  • Plastic bottle caps
  • Popcorn
  • Grapes
  • Safety pin
  • Metal nuts or screws

Denser objects will fall further down the column of liquids (some may fall all the way to the bottom), while less dense objects will stop somewhere along the way. You can use this as an easy way to compare the density of a liquid to a solid.

Using these density lessons will also help you make a more precise calm down jar.

Here is a fun printable to help you record the results of your experiment.
Print at 4x6 or 5x7

More Easy Science Fun


  1. Love doing this with my children. They would love it.
    Thank you for sharing it with us #pintorials

  2. this looks so fun! I will have to try it over our summer vacation.

  3. This looks like a fun activity. I will have to try this with my little one when he gets back.

  4. I loved this experiment when the kids were smaller. (Too bad they have to grow up!)

  5. What great experiment for younger ones! I think I'll try this with my son over the summer.

  6. oh how fun!! I don't have children (yet) but this is such a good idea!

  7. I love the idea of putting different objects inside to see if they sink or float. Great way of demonstrating density. Great use of colors as well!

  8. I am preparing my weekly linky party today and I want to feature this post in Kids Learning Printables Linky Party #9. Thanks for the great idea and keep up the good work!



  9. I love this experiment, so simple and I think kids will understand it.

  10. My son is getting to the age where he really loves activities like this. I cant wait to try it!


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