Changing Egg Density
Does an egg float or sink in water? What if we change the
For this experiment, you will need two glass jars that are large enough to hold
a few cups of water each, two eggs, some salt, some sugar and some water.
Let’s see if an egg will float when placed in water, and what will happen to the egg if you change the density by adding sugar or salt.
First,you can put a few cups of water into each jar, and then place one egg into each
jar of plain water. Do the eggs float in the water or sink to the bottom?
Next,take one jar and add a teaspoon of sugar. Did it make the egg float? (Or sink
if the egg was already floating?)
Add a few more teaspoons of sugar, does it change at all?
Take the other glass jar with the egg in it and add a teaspoon of salt. Did it
make the egg float? (Or sink if the egg was already floating?) Make sure to record and
compare your results.
Hard boiled eggs with shells attached
Glass or plastic cups containing clear vinegar
An egg (or eggs) with the shells attached are placed in containers of clear
vinegar. Leave the eggs in the vinegar for three days. (So this is not a
quickie experiment…but still worth it.)
After three days, take the eggs out of the vinegar and wash the shell
off of the egg. This should come away easily with gentle handling. The eggs are
rubbery, bouncy and can be enjoyed as a tactile experience!
Squeezing and poking the eggs should be encouraged – not too roughly of
course. And then the eggs can be taken outside and dropped to test their
special bouncing qualities. If you feel like it they can be tested to
What’s Happening? The egg’s shell is constructed from calcium carbonate and
the acid vinegar eats away the shell. The inner membrane of the egg remains and
the egg material should now feel rubbery.
Extra Fascinating Facts
Calcium carbonate is a chemical compound with the formula CaCO3.
It is a common substance found in rocks in all parts of the world, and is the main component of the shells of
marine organisms, snails and pearls, in addition to eggshells.
Calcium carbonate is the active ingredient in agricultural lime, and is usually the principal cause of hard water.
It is commonly used medicinally as a calcium supplement or as an antacid.
Thanks to: www.easy-kids-science-experiments.com