How Does Salt Water Make an Egg Float?

Salt increases the density of water, allowing an egg to float.
••• Steve Baccon/Photodisc/Getty Images


••• Melissa Kirk/Demand Media

Fill two clear glasses with lukewarm water. Pour 1 tablespoon of salt into one glass, and stir until the salt dissolves. Gently drop a fresh egg into the plain water. The egg will sink to the bottom. Remove the egg and place it in the saltwater. The egg will float.

How It Works

••• Melissa Kirk/Demand Media

Objects sink in liquids when their density is greater than that of the liquid. Conversely, objects float when the density of the liquid is greater than that of the object. An egg has greater density than plain water, so it sinks. Salt increases the density of water, however. The denser the water, the easier it is for an egg or other object to float.

More About Density

••• Melissa Kirk/Demand Media

The higher the salt content of water, the higher an object will float. If you add less than 1 tablespoon of salt to a glass of water, it is possible to make the egg float in the middle. This also can be accomplished by adding 1 tablespoon of salt to water and not stirring. Because the salt is denser than the water, the salt will sink. When you drop the egg into the water, it will sink through the plain water until it reaches the saltwater at the bottom of the glass. The density of the saltwater prevents the egg from sinking any lower, so the egg will float in the middle of the glass.

Related Articles

How to Float an Egg in Water
Kids' Density Experiments With Salt, Water & Eggs
How Much Salt Does it Take to Make an Egg Float in...
How to Make Things Float in Water
How to Convert Salt Water into Freshwater (Drinking...
How to Make a Five Percent Solution With Salt
Why Does an Egg Shrink in Different Solutions?
How to Increase the Density of Water
Science Project: Why Salt Makes Things Float
Third Grade Science for the Measurement of Density
Why Is Salt Water Heavier Than Tap Water?
How to Make an Egg Float Using Salt for a Science Project
2nd Grade Water Density Projects
Four Biggest Differences Between the Ocean & Fresh...
How to Light a Lightbulb With Saltwater
How to Find Density
Science Project on How to Float an Egg
How to Prepare Supersaturated Salt Water Solutions
Science Project Egg Experiments