Spin Eggs, Spin!

This lesson developed by Michelle M.
Recommended Ages: Preschool and Early Elementary


Do all eggs spin the same?
What happens to a hard boiled egg when it spins?

What You Need

  1. 1 hard boiled egg
  2. 1 raw egg
  3. 2 dinner plates or a pie pans

What You Do

  1. Put the hard boiled egg in the middle of one of the plates or pie pans.

  2. Spin the egg around like a top.

  3. Put the raw egg in the middle of the other plate or pie pan.

  4. Spin the egg around like a top.

  5. Watch the two eggs. What do you see? Is one egg spinning around? Is one egg struggling to spin?

What Is Happening

The hard boiled egg spins around easily because it is a solid. The insides of the egg have been cooked- it is not a liquid inside. A solid object has what we call a "fixed balance point." The raw egg is liquid inside. The liquid is slashing (sp?) aoun d as it moves- there is no balance point in it. This makes it hard for them to spin.

For fun you could pretend you are doing some magic with friends. Get several raw eggs and one hard boiled egg. Get a large pizza pan. Tell your friends that one of the eggs is hard boiled and that you can tell which one it is. Let them take a look at the eggs to see they all are eggs and that none of them is marked. They all look the same. Put the 3 or 4 raw eggs and the 1 hard boiled egg on the pizza pan. Get all of them spinning. You can pick out the egg that spins the best and lift it up and te ll your friends, "this is the hard boiled egg." Break the eggshell open and show them the inside. They won't know how you could tell!