How do you tell the difference between a hard-boiled egg and a raw egg without cracking them? Can you spin an egg and make it stand on end?

What you need:

Hard-boiled egg

Raw egg

Kitchen table

Marker pen

How to:

Ask an adult to hard-boil the egg for you.

Label the hard-boiled egg with a H. Label the raw egg with a R. Spin both the eggs on the kitchen table. What do you notice? Spin both the eggs again. stop them by putting your finger on them lightly. What do you notice? Put the raw egg to one side. Spin the hard-boiled egg again and make it spin very fast. What do you notice?

The hard-boiled egg should spin on its end!

What's happening?

Now you can tell the difference between hard-boiled eggs and raw eggs, just by spinning them!

Hard-boiled eggs are easy to start spinning and easy to stop spinning.

Raw eggs are harder to start spinning and keep turning a little bit when you try to stop them.

Why?

Hard-boiled eggs are solid inside. In the raw egg, the liquid inside the egg slides about and stops the egg from spinning as fast.

When you stop the hard-boiled egg, it stops quickly. When you stop the raw egg, it keeps turning a little bit. You have only stopped the shell, not the liquid inside. The liquid is still moving, which causes the shell to keep turning.

Hard-boiled eggs will spin on their end if you spin them fast enough. The egg saves energy by spinning on its end and making a smaller circle.