Before you go and think I’m crazy nuts, our bouncing egg science experiment involved a safe acid (grins). Zachary has loved all the hands-on projects to go along with his Christian Kids Explore Chemistry this year, and this one to see how acid interacts with calcium carbonate was no different.

That said – it was super easy to pull together and one that every family should do (did I mention it was easy?). Aside from learning about chemical reactions, what’s not to love about an egg that can bounce?!

Bouncing Egg Science Experiment

The main purpose of this experiment was to test the reaction of a weak acid (white vinegar) with calcium carbonate (CaCO3 – an eggshell). If you’d like to try this at home, you only need a few items:

• a quart mason jar
• a raw egg (make sure the shell isn’t cracked)
• white vinegar to cover egg
• safety glasses (we picked up a box of 12 here)

Here’s the quick science explanation:

An egg shell is made up of calcium carbonate, so when the egg is soaked in vinegar (about 4% acetic acid) a chemical reaction begins. Carbon dioxide is released (the bubbles you see on the shell) as the vinegar begins to dissolve the shell. The membrane of the egg will remain (the rubbery part of the egg).

The egg was supposed to soak for 24 hours and then observations were to be tracked. Ours ended up soaking a bit longer (as in four days) because it stayed in the schoolroom over the weekend and we completely forgot out it. It was a lovely stink come Monday morning. (grins)

The vinegar was carefully drained from the egg and GENTLY rinsed off under clean water. (May I stress gently again?)

We pulled out another raw egg to compare and contrast to our experiment. The egg that had been soaked felt completely rubbery and could be gently squeezed (again with the gentle). The entire shell had dissolved thanks to the chemical reaction with the vinegar.

Size-wise there was a significant difference as well. When the egg soaked in the vinegar,  some of the vinegar and water in the vinegar moved through the membranes of the egg and into the egg. Egg membranes are semi-permeable so water can move through them (an example of osmosis).

Trying to find the yolk now the shell was missing, we grabbed a flashlight as well to see how translucent the egg was. 

The fun part came in the bouncing of the egg. To keep the counters clean, we pulled out a tray and tried dropping it from different heights to see if it would break.  You can see a short (and slightly blurry – sorry!) video here or below.

Once we were done bouncing and playing with the egg, we popped it with a fork to feel the membrane of the egg. (And yes, we all thoroughly washed our hands when we were done!).

This is one of those experiments we would like to do again, but this time with several eggs in different jars and then try a few variables when we are done soaking them all in vinegar: moving one to plain water, one to cornstarch, and letting one sit out on the tray to see what happens to them all.

There’s so much more we could do, but this was a fun start to our egg experiments.

More Science Fun

If you have some time and need a few ideas, we worked on both of these projects this year and had a blast with them (especially the cookie skillet!).

Atomic Cookie Skillet Models – learn more about the Periodic Table and how what atoms consist of with this fun (and edible) project!

Building Atom Models – build simple atoms together and make chemistry hands-on for your kids with this easy activity.

One of the things that I’ve loved about our Chemistry science program (aff link) for Zachary this year is the hands-on aspect of the program. He is a boy that needs a little something to do with his hands every now and then, so it has fit in very well for us. As we’ve been learning about atoms together the last several weeks,  Building atom models and getting a 3D look at how an atom might actually appear has been a great way to visualize what we’re talking about. Quite obviously, these models are not to scale and a whole lot larger than the real thing. (grins)

In our model we used Styrofoam balls to represent the protons, neutrons, and electrons. In an atom, the protons and neutrons are in the nucleus (the center of the atom), and the electrons surround the atom. In diagrams you often see the electrons represented by elliptical lines moving around the nucleus.

Building Atom Models

We chose to build a model of a lithium atom and used the following supplies. If you would like to make a different atom, the number of styrofoam balls will differ based on the number of neutrons, protons, and electrons in the atom. See below for how to calculate those numbers.

• 7 styrofoam balls – we used ones that were about 2” in diameter
• 3 styrofoam balls about 1 inch in diameter
• 3 pipecleaners
• toothpicks
• red, yellow, and blue paint
• paintbrushes

1. Paint four of the 2” balls yellow (neutrons) and three of the balls blue (protons).
2. Paint the 1” balls red (electrons).
3. Using the toothpicks, connect the yellow and blue balls together, making sure they touch each other. We broke out toothpicks in half so they wouldn’t poke through too much.
4. Connect each electron (red balls) to one of the protons (blue balls) using the pipe cleaners.

The model was a great way for us to understand a little better how atoms look. It was fun to talk about how many balls we would need to make some of the other atoms such as gold (79 protons/electrons and 118 neutrons – that would be a very large model!). We definitely figured it would be easier to stick to some of the more smaller numbered atoms on the periodic table!

To Build Different Atom Models

If you are trying to figure out how many neutrons, protons, and electrons an atom has, there is a way to work it out without needing to look up each atom one at a time. Each atom has an atomic number and an atomic weight. The atomic number tells you how many protons and electrons that atom contains. The neutrons are determined by looking at the atomic weight of the atom, rounding it up to the nearest whole number, and subtracting the number of protons. Usually you can find both numbers on your periodic table of elements.

Atomic weight = Protons (atomic number) + Neutrons

Additional Atom Model Ideas

Don’t care for styrofoam balls? Check out this idea on the Bright Idea Press blog using playdough (secretly I almost wish I would have seen this version first). Zachary loved creating and painting the model we did though, but I’m filing away this idea to use another time!

A few weeks ago we made edible atom models – and we enjoyed every single bite! Check out our atomic cookie skillet models for the recipe and instructions.

If you’d like to learn more about the homeschool chemistry program we are using, you can find out more here. Feel free to check out the rest of our homeschool curriculum choices as well!