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Floating Egg - Salt Water Experiment

This activity is a fun way to talk with children about saltwater and how it is different from freshwater. After making their predictions about whether the objects will sink or float in the saltwater or freshwater, children will learn all about density and how this can affect other objects.

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Will saltwater make you float?

Have your child learning more about saltwater density through this fun and simple activity! Grab two glasses and fill them with warm water. In one glass add salt and mix it up well. Then have your child predict what will happen when they add the eggs. Gently add the eggs to both glasses and watch as one floats but the other does not. 

📚 Books to explore: Why is the Sea Salty? By Benjamin Richmond; Rivers, Seas and Oceans by Mack Van Gageldonk; and The Magic School Bus on the Ocean Floor by Joanna Cole.

🌊Did you know? Saltwater is denser, which causes you to float easier. 

🗺️ Where is saltwater? Grab a map and look over it with your child to point out where saltwater oceans are located.


For this activity you will need:

2 glasses (large enough to hold an egg)

Warm water 


2 eggs 


Learning Outcomes




Using descriptive language to explain, explore and extend


Using sentences to describe objects and events


Step 1:

Fill the glasses roughly ⅔ full with water.

Step 2:

In one glass add 3 tablespoons of salt and mix well (the salt needs to dissolve.

Step 3:

Have your child predict what will happen when you add an egg to the glass with just water and the same for the one with salt. 

Step 4:

Have your child gently place an egg in both glasses with a spoon and see what happens.

⬆️ For older preschoolers: Have your child experiment with different objects.

⬇️ For younger toddlers: Have them add the salt and stir it up to better understand there is something in the water

Playful Questions

What is in saltwater? 

Can we drink saltwater? Why?

What animals live in saltwater? 

Would you float better in saltwater?

What is the largest mammal that floats in the ocean?

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