Eggs are the one thing that virtually everybody can get everywhere, all over the world, at a reasonably cheap rate. This is important as they can be used for a wide range of cheap science fair projects to demonstrate a large number of scientific principles!
First, they can be used to teach embryology and development. This can be done two ways, one by incubating several and opening one a day will show how the systems of a developing embryo form. The embryos can be placed in glass jars and stored for some time before the Science Fair. Another way to do this if eggs are limited is to take just a few and cut a small circle in the top of the shell and remove it; put candle wax around the edge (Glues are frequently toxic to the embryos) and mount on a small glass pane or slide cover. Just make notes and sketches of the egg as it develops. Always use tow or three eggs in case one dies or gets broken.
Another easy project with eggs is shape and shell strength. Set the egg at different positions and then place weights on them, see which way holds the most weight. You can also include angles and math for triangulation or even try different shaped eggs. Try bouncing the eggs and determine the differences between steady pressure and impacts; compare the results to the shapes of the old space capsules!
Chemistry is neat using eggs and eggshells. Show what happens when an egg is placed in vinegar. Crush the eggshells and test the pH. Mix the egg white with vinegar! Find out what happens and why, the students can even eat this experiment!
Microbiology and cell metabolism can also be demonstrated. Dissolve off the shell using vinegar and you end up with a very large “cell”. Put it in solutions of varying density by mixing salt and water. The shell will sink and expand in some solution and shrink and float in others. An excellent example of osmosis and how fluids enter and exit cells; all with just an egg and no microscope or dyes!
More microbiology needed? Take whole, uncracked eggs and have them put in different areas and conditions. They can be placed in old socks, piles of dirt or in dirty water. Leave them for a week and then check to see which, if any, rotted. Why didn’t they all go bad? The shell protects them and so does the egg whites!
These are all good, practical and yet easy, science fair project using that simple little egg. How many others can you think of?