Explore the Miraculous Strength of Eggs
In this simple science experiment, kids explore the amazing and unexpected strength of eggs.
Simple explanation: Egg shells are thin and fragile, but their round shape makes them exceptionally strong. This is important in nature, because otherwise the eggs would break when the mama sits on them.
Detailed explanation: When you apply even force to an egg -- as when you squeeze it -- it is almost impossible to break. But when you apply an uneven force, like striking it on one side, it breaks very easily. This is due to differences in how the force is distributed around the shell.
The strongest position for an egg is sitting on its fatter, rounder end with its pointy end facing up. That is why most eggs are sold in cartons with the pointy end up. Take a look the next time you are at the store.
A similar arched form has been used in architecture for thousands of years because it is so strong. Think of domes on buildings and arches in bridges and doorways. Be sure to look for these egg-inspired shapes all around you this week.
Safety Notes
Children should not touch or eat raw eggs. Any surface touched by raw egg should be thoroughly washed.
Materials
- Raw egg - 1 of this item per student
- Zipper sandwich bag - 1 of this item per student
- Container of 1 dozen raw eggs - 1+ of this item per class
Instructions
Note: To avoid wasting food in this activity, see if you can get containers of expired eggs from your grocery store.
Begin by asking your little scientists: How easy is it to break an egg? Can you break it just by squeezing it?
Now demonstrate how difficult it is to break an egg by squeezing it. (Unless there is a defect in the egg, it will be almost impossible to do.)
Place an egg in a zipper baggie and invite the scientists to try squeezing it themselves. Can they break it? You can do one egg for a whole class, or give one to each student. Just be sure they follow your directions and don't smash the egg on the table!
Once they've seen how strong the egg is, demonstrate how easy it is to break it open against a hard surface. Why do they think this is? Invite them to crack their own eggs and examine the broken shell.
If you are feeling adventurous, you can also try to step on a container of a dozen eggs without breaking them. It is possible to do this; watch this video from Steve Spangler: https://www.youtube.com/watch?v=Xckhg7Ns8so&t=174s. We couldn't figure it out, however! Either way, the kids will find it entertaining.
