Step 3

Before we explain why the egg floats, let's do one more experiment. Take another cup and put some water with food coloring in it. Now gently pour it over a spoon into the floating egg glass. The reason for the spoon is to keep the colored water from mixing with the sugar water in the glass.

How does it work?
A regular egg is more dense than water and that is why it sinks. As a simple explanation, density is the amount of matter (stuff) in an object compared with its size. For example, a balloon may be the exact same size as a bowling ball, but it is a lot less dense (it is the same size but much lighter).

When we mix sugar into the water, this causes the density of the water to increase because there is now more "stuff" in it. Now, the sugar water is more dense than the egg, so the egg floats.

Digging deeper.
So what happened when we poured regular water on top? Remember, when you added sugar to the water it became more dense. So when the less dense (regular) water was carefully poured on top of the more dense sugar water, it floated on top. Since it was colored first, you could easily see the less dense water on top of the sugar water.

Try this:
What would happen if you tried the above experiment with salt? Would the results be the same? Would this experiment work with anything that dissolves in water? Try some experiments with different substances to come up with your conclusions.