Kids Science Experiments

Egg Floats

Want to make an egg float? Yuck! Not *that* kind of float, there is not any ice cream here. Let's see if we can make an egg float in water without boiling it.

Our Science Experiment

We are going to put an egg in water and try to make it float to the top.

What you need

a raw egg
two glasses of water (1/2 full)
14 tablespoons of salt

How to perform this experiment

Put the egg in one of the glasses of water that is half full. Observe what happens. Now, add the salt a little at a time, stirring gently and observe what happens. Take out the egg and dry it on a towel. Very slowly, add the fresh water (the other glass of water) to the salty water you just made. Do NOT stir this one. Now lower the egg slowly back into the water.

Watch!

When you first put the egg in the fresh water, it sank to the bottom. As you added salt and stirred, you made the water more dense (it now weighs more) and the egg floated slowly to the top. Then you added fresh water to the salty water and didn't stir, so the waters didn't mix. The egg sunk to the bottom of the fresh water, but floated on top of the salty water, thus suspending it right in the middle of the glass.

Why did it do that?

When the liquid got denser it created a greater buoyancy, or upward lift. Mixing the salt with the water made it denser.

I wonder what would happen if

I wonder what would happen to the egg if I put it in my water sandwich?