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Water Balloon Science Experiment

Kids love playing with water, which makes learning from water experiments so interesting and exciting. How can we make it even more fun? How about adding some water balloons to our science? Children in preschool through grade 6 will enjoy this Water Balloon Science Experiment.

WOW! Water Balloon Science Project for Kids to explore what floats in a completely new, fun, and engaging way that kids will love!! REALLY cool science experiment for kindergarten, first grade, 2nd grade, 3rd grade, 4th grade, 5th grade, and 6th grade students for science fair proejcts or homeschool #science #kidsactivities #density

Science Projects for Kids


My kids have been obsessed with experiments exploring the properties of water lately. In a recent science fair my son did a presentation on “does it float” and played with a variety of different concepts. Since we have already done quite a lot of flotation experiments and water projects for kids, I knew I was going to have to come up with something unique and different to capture their imagination. When I came up with the idea to use water balloons, I knew I had hit a home run! My kids absolutely loved this water balloon science experiment and keep asking to do it again and again.

Water Balloon Science Experiment

The idea of this density science project is to explore what liquids float, and which ones sink, by filling water balloons with different liquids.

water balloon science project

What do I need for this water experiment?

  • A large container filled with water. Look for something with a depth of at least double the size of your water balloons when they are filled. Deeper is even better!
  • Water balloons
  • 60mL Syringe
  • Different liquid solutions (some ideas: water, vegetable oil, corn syrup, salt water, sugar water, juice, etc.)
  • Permanent marker


Science Experiments with Water

I highly recommend you do this activity outside. Water balloons are very easy to pop! I also recommend you fill multiple balloons with each type of liquid. That way if one pops you have some back ups.


Density Experiments

One note of caution: We found vegetable oil tended to weaken our water balloons making them more prone to popping. We did not experience this with any other liquid type, only vegetable oil.

Water balloons are meant to be filled under pressure. Using the syringe you can easily fill the balloons. We found a 60mL syringe made perfect, egg sized water balloons. Simply wash well after each type of liquid so you don’t cross contaminate.

Here are some ideas for what to put in your balloons:

  • lamp oil
  • rubbing alcohol
  • vegetable oil
  • dish soap
  • milk
  • maple syrup
  • corn syrup
  • honey
  • salted water

Filling the balloons with a syringe is a fantastic fine motor strengthening activity, but prepare them outside or in an easy to clean up space, as it can get messy.

using a 60mL syringe fill the water balloons with various different liquids to perform the density experiment

As you fill each balloon make sure you label it so they don’t get mixed up.

Once your balloons are filled, head over to your container. This is the perfect time to ask for some predictions. Will it sink or will it float? Then place your balloons in the water and watch what happens.


Summer Science

The science behind this water balloon experiment

Different types of liquids have different densities. In this experiment we are able to see which liquids have a greater density than water causing them to sink, and which ones are less dense than water, which allows them to float.

About the author

Beth Gorden

Beth Gorden is the creative multi-tasking creator of 123 Homeschool 4 Me. As a busy homeschooling mother of six, she strives to create hands-on learning activities and worksheets that kids will love to make learning FUN! Beth is also the creator of www.kindergartenworksheetsandgames.com where she shares Kindergarten spedicif worksheets,& educational ideas.

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