How To Make An Egg Float

For a unique science project or just a neat trick to amaze your friends, learning how to make an egg float is simple and quick. Normally, eggs sink in water as the density of an egg is greater than the density of water. To make an egg float, you need to increase the density of water and that's where salt comes in. By dissolving just enough salt in water, you can make the egg float.  

To make an egg float, you will need:

  • A standard drinking glass
  • One cup lukewarm water
  • Four-to-five teaspoons salt
  • One egg
  • A spoon
  1. Pour the water into the drinking glass. Be sure the water is lukewarm as it will allow the salt to dissolve easily.
  2. Add four teaspoons salt to the water. Stir with the spoon until completely dissolved.
  3. Gently drop the egg into the glass. If the egg sinks to the bottom, remove the egg.  
  4. Add more salt, half teaspoon at a time. Stir to dissolve the salt. Gently test the mixture by adding the egg to see if it floats. The desired outcome is to have the egg float in the center of the glass, rather at the top of the water.
  5. Once you've reached the proper consistency, remove the egg. Gather friends and family around to show them your new trick, dropping the egg into the water and watching it float.

To enhance the performance, use three glasses, one with regular tap water and one with six or more teaspoons of salt dissolved in the water. Place the egg in the regular water to show that it sinks, then into the extra salty water to show that it floats on the surface. Finally place the egg in the salt water described above to show that it floats in the center of the glass.


Resources:

Floating egg experiment