How Do Sharks Float?
Updated: Jun 25, 2021
This oceanic educational activity will allow your preschool or school-age child to explore the world of sharks and how a shark’s liver keeps them buoyant. Children will be able to compare two balloons, one filled with water and the other filled with oil, to observe which is more effective at staying afloat. Younger children may need assistance with using a sharpie or tying the balloons. This activity is guaranteed to keep your child interested and educated!
What You Will Need:
Large bowl or tub of water
Oil (cooking, vegetable, etc.)
Permanent marker or Sharpie
Tip: Ask an adult’s permission before using the vegetable oil or permanent marker!
1. First, ask an adult for help before doing this experiment because we will be using vegetable oil, balloons, and a sharpie.
2. Next, blow up one of the balloons (or ask a guardian to blow up the balloon) to get the balloon stretched out for the oil or water! After you blow up the balloon, empty all of the air out.
3. Next, put your funnel inside the “neck” of the balloon. The funnel will make it easier to add the water and oil to your balloons.
4. Pour some water, through the funnel, into one of your balloons. Pour slowly to make sure you do not overfill the balloon!
5. Pinch your balloon at the bottom of the neck and empty the extra water. Remove the funnel and tie the balloon near the neck. Make sure you’re letting in as little air as possible, which may mess up the experiment! Twist the neck of the balloon to seal off the water.
6. Next, repeat steps 4-5 with the oil. Be sure to pour the oil slowly so you do not waste any oil!
7. Pour out any excess oil in a spare glass after twisting off where the oil stops at the neck of the balloon.
8. Using your sharpie or permanent market, label your balloons with which one has water and which one has oil. Next, draw your shark faces! Pinching the balloon may make drawing easier.
9. Now you’re all set to test which one has an easier time floating!
10. Place your “water” balloon and observe how well the balloon floats. Do the same for the “oil” balloon, and then ask yourself: which one is having an easier time staying afloat?
11. The oil balloon should have an easier time floating since oil is less dense than water, which is found in a shark’s liver!