Spring is a time of rebirth and renewal—and eggs! Many animals lay and incubate eggs in the spring, and in some cultures spring is a time in which kids paint, hide and eat lots of eggs. This makes it a great time to not only take a close look at eggs, but also to experiment with some of the things we can do with them. This activity is the first in the Incredible Egg series of activities, which are designed to be done during the Spring—start your students off with this and other “egg science” activities, then move on to egg art, and finally take the Egg Drop Challenge!
At least 10 dozen eggs (white eggs are preferred, brown are OK)
3–4 older eggs (see Preparation)
Ziploc bags (1 package, gallon size)
Food coloring or egg dye
Cardboard, thick construction paper, or pieces of wood (4” X 6” or 5” X 7”, 1 or 2 inches thick)
Several thick books
The following preparation is for ALL of the Incredible Egg activities. This page gives instructions for the “How Strong is an Eggshell?” activity, but the preparation instructions here will get you ready for all Egg Science, Egg Art and Egg Drop Challenge activities as well. Get your eggs ready and try all of these activities as you explore science, engineering, art and math…all with the simple (but pretty incredible) little egg!
In the Incredible Egg activities, your students will investigate some of the physical properties of eggs, and will then make paintings and mosaics using different parts of store-bought eggs. The Incredible Egg series includes the following activities, found in this curriculum:
Egg Science Activities:
How Strong is an Eggshell? (this activity)
The Emperor’s New Egg
Raw or Hard-boiled?
Fresh or Old?
Egg Art Activities:
Egg Dyeing with Natural Dyes
Egg Drop Challenge
The “Incredible Egg” activities use every part of the egg – the shells, whites (called “albumen”) and yolks. Use the instructions below to prepare each egg part for the activity series:
Preparing Eggshells – Your first step in preparing the materials is to prepare eggshell halves for the “How Strong Is An Eggshell” activity, described on this page. Crack an egg open, being careful to crack it in the middle, making 2 halves that are as close to the same size as possible. Separate the egg yolks and egg whites into different bowls or containers (See Figure 1 for an illustration). If you mess one up, that’s perfectly OK – you’ll need lots of crushed eggshells and the whites and the yolks for the Incredibe Egg – Egg Art activities (see above). If one doesn’t break quite right, separate the white and yolk and put the shell aside for “Eggshell Mosaics”, then crack another egg to try again.
Whites and Yolks – The Egg Art activities use the whites and yolks of the eggs to make homemade paint. There are two methods for separating whites from yolks, the less messy way, and the fast way:LESS MESSY METHOD: Lightly crack the egg on the edge of a bowl but don’t open it. Turn the egg upright, carefully open the shell into two halves (do this over the bowl), keeping the liquid part of the egg in the lower half. Pour the egg from one half of the broken shell into the other, letting the egg white fall into the bowl but keeping the yolk intact in the shell halves as you pour. Repeat until all the white has fallen into the bowl, leaving only the yolk in the shell. Pour the yolks into a separate bowl or container. Set aside the two eggshell halves and repeat this process until you have 20 good eggshell halves for the How Strong Is An Eggshell activity (described in these instructions). Look for eggshell halves with no cracks in them. Carefully rinse these shells with water and set them aside to dry. THE FAST METHOD: If you don’t mind getting a little messy, you can also separate eggs by cracking the shells open, pouring the white and yolk into your hand and letting the egg white ooze through your fingers into the bowl below, leaving the yolk in your hand. This is quicker, but messier. Make sure you wash your hands before and after! Store the whites and yolks in separate containers in the refrigerator.
Boiling an Egg – Next, hard boil 1 egg using these directions: place the egg in a saucepan with enough cold water to cover it by 1 inch. Bring the water to a rolling boil over high heat, then reduce the heat to a medium boil and cook for 10 minutes. Remove the egg and place it in a bowl of cold water or ice water and let it cool completely. Place this egg in the refrigerator—remember which one it is—it will look just like the uncooked ones! You’ll use it for the Raw or Hard-boiled? activity.
Set 1 dozen eggs aside in the refrigerator.
Egg Art – The remaining eggs should be prepped for the Egg Art activities. The instructions for doing those activities can be found on the activity pages listed above. Separate the eggs as you did above, but don’t worry as much about making nice, neat eggshell halves. You’ll need to prep several dozen eggs (you need a lot of shells). As you did before, save the whites in 1 container and the yolks in another. Rinse off all of your eggshells and set them aside on paper towels to dry. When they are dry, place them in a Ziploc bag, squeeze the air out of the bag and zip it shut. Place a towel over the bag and carefully crush all of the eggshells until they are in little pieces around the size of split peas or grains of rice. It shouldn’t take too much time—shells crush pretty easily.
Once all of the shells are crushed, divide them into a few Ziploc bags. In 1 bag, drop a few drops of blue food coloring, seal the bag and shake it until the coloring has spread out evenly. Add a few more drops and repeat until the shells are a color you like. Repeat this process with the other bags of uncolored shells—make red, yellow, green, purple, etc. Leave 1 bag uncolored so you have white shells to work with. If you would prefer, you can color these crushed eggshells using egg dye instead—follow the instructions on the dye packet.
Finally, try to collect eggs of different ages for the Fresh or Old? activity. Try to find eggs that are 1–2 weeks old, 1–2 months old and older. Bring these in from home, or ask staff/students to see if they have older eggs in their refrigerators at home. Using permanent marker, label these eggs “egg A”, “egg B”, etc. so that you know which is which.
Ask your students if they’ve ever cooked or dyed eggs. Have they dropped an egg? What happened? Do they think that eggs are strong or fragile? How much weight do they think an eggshell can hold?
See how much weight eggshells can support!
Doing the Activity
You should do this activity as a demonstration, with your students gathered around the table or floor.
Place the shells, broken side down, on a table or on the floor. Arrange them as if they were on a square, with each eggshell at a corner. Make this square a little smaller than the largest book you have, and tell your students that you are going to pile books on top of the eggshells until they break. Place the first book (gently!) on top of the shells. Did they hold the weight?
Let’s Talk About It
Did the results surprise your students? What did they think would happen? Ask your kids to predict how many books the shells will hold before they break.
Build On What They Talked About
Add more books until the eggshells crumble. If you have a scale, weigh these books to see how much weight the shells held. Try again with more eggshells if you’d like, and let some students place the books.
Ask students to think about what it is about the egg shells that make them strong. If not mentioned, point out the shape, and ask them if they can think of any other strong structures or objects that are that shape.
While eggshells are pretty fragile in the middle, they are quite strong from end to end. If you look at half of an eggshell you should see an arch shape—one of the strongest shapes around! The middle of the egg, where we usually crack it, can’t take advantage of that shape.