Science Models
Science Fair Projects

Published on Sep 16, 2023

Can an Egg Float on Salt Water


The objective: To determine at which concentration salt water has to be to be able to float an egg.

Some objects float on top of the ocean, and others sink to the bottom. Did you know that if you put an egg in a cup of water it will sink to the bottom? However, if you add enough salt the egg will float back up to the surface. Adding salt to water increases the density of the water, because the salt increases the mass of the water without changing the volume.

Can an Egg Float


The purpose of this project is to determine what salt concentration will float an egg.


My hypothesis is that the egg will float according to the amount of salt water in the tap water.


• 5 Eggs

• Permanent marker

• Table salt (1 cup)

• Water

• Measuring cup, Liquid

• Large container, such as a large bowl or cookind pot. The bowl or cooking pot must be able to hold 5 cups.

• Spoon for stirring

• Bag of clear 16-oz. Plastic cups

• Soup spoon for egg transfer

• Notebook


1. Take five eggs out of the refrigerator, and label the eggs using permanent marker from 1-5, then leave them in a safe spot to warm to room temperature.

2. Take 1 cup os salt dissolved in 5 cups of water. Pour 3 cups of water into your large container. Add 1 cup of salt. Stir to dissolve the salt in the water it will take about (5 to 10 mins) of stirring.

3. Label five cups 1-5. Cup 1 will have only salt water and cups 2-4 will have both tap and salt water, and cup 5 will have only plain tap water.

4. Add 3/4 of your salt water in cup 1. Add 3/4 of tap water into cups 2-5. Add 3/4 of salt water and add it to cup 2 then mix. Add 3/4 of salt water and water that has been mixed in cup 2 to cup 3 and mix.

• Then repeat the same step again but take the salt water and tap water that was mixed in cup 3 from cup 2 and take 3/4 of salt/tap water from cup 3 and put it in cup 4 and then mix.

• Starting from cup 5 work your way up to cup 1, then test an egg in each cup and see if it will float. Use a soup spoon to left the egg in and out of the cups.

• Finally jot down what happened to each egg in each cup.


Can an Egg Float


In conclusion, my hypothesis was correct. In some cups the eggs did not float because they had more tap water in them than salt water, and in some cups the eggs did float because they contained more salt water. Through my experiment, I learned that objects don't float in the sea because of their weight, they float in the sea because of the amount of salt.






Science Fair Project done By Hasrat Mann