A leisurely breakfast and a cool experiment. Sounds like a pretty great Saturday morning if you ask me. Thanks to the folks over at tinkerlab we were able to have both.
I love the ease of this experiment. Don’t let the presentation photo fool you- It’s really just measuring and mixing. All items used I had on hand. I also felt like we got a big payoff. We were able to watch the geodes grow over a few days, and then end results were gorgeous.
First step is to use a knife to knock the very top off the egg shells. The number of eggs depends on how many solutions you are going to try. Each solution will fill two eggs. Empty the yolks into a bowl and mix up your favorite omelette (that’s where the breakfast comes in). Rinse out the egg shells and peel the membrane from the inside.
You can look at the full experiment on the link at the start of this post, but we basically mixed a 1/4 each of the following materials with a 1/2 cup of very warm water.
Borax (pay attention when kids are handling borax. You do not want this ingested)
Sugar (we did not get sugar crystals to grow)
They also recommended trying sea salt, cream of tartar, or baking soda. Add food coloring or liquid water colors so that each solution is a different color. Make a sheet to track the color of each solution.
The boys were not very patient about getting each substance to dissolve in the water. We had undissolved salt and sugar in the bottoms of our eggs. This did not seem to impede growth.
The geodes will start to grow in 1-2days as the liquid evaporates. We dumped the remaining liquid out after about four days so we could examine our crystals. I’m sure you could let them keep going until all liquid evaporated.
This is the basic experiment. There are many ways to extend learning.
One thing we did was to examine the materials beforehand, so we could see if the crystals that grew were similar to the original shape of the substance. For instance, the Borax looked like small flakes, and the crystals it grew looked a bit like snowflakes. We tracked this on our sheet by drawing pictures of what each substance looked like prior to mixing with water.
We also looked through a microscope to see what our substances looked like up close. The addition of a microscope need not be expensive or complex. We purchased a simple microscope at the thrift store for around $6. So far, it has been sufficient for experiments, and adds a fun dimension.
This can also be a great opportunity to build vocabulary. Explain what a solution is as you mix the ingredients. Ask them what their hypothesis is. Talk about what results were yielded. Define crystallization. If you have crystals that grow on the outside of the shell, talk about osmosis.
The best part is that if all goes according to plan, in a couple of days you will have amazing crystals like these! Happy experimenting!