Making Crystals with Preschoolers

In honor of Valentine’s Day, we decided to create beautiful crystals!  The kids designed their own shapes and were able to take home a gift for a loved one.

The larger heart was formed in a leftover pasta sauce jar and the smaller heart was made in a baby food jar.

Materials:

• boiling water
• Borax
• pipe cleaners
• string
• long object, such as a pencil, to place across the mouth of the jar
• glass jar, such as a mason jar or baby food jar
• spoon or something to stir the solution- I used a disposable skewer because I don’t want the Borax to touch anything that I am planning to eat with.

I started by making this experiment at home, as I usually do, so I could have an example and anticipate any issues.  First, I boiled water in a kettle.  As I waited, I added about four tablespoons of Borax per cup of water into mason jars and baby food jars.  I estimated the amount of water and probably added more then I needed to.   Then I cut pipe cleaners and shaped them into hearts.  I found out the hard way that your shape (heart, spiral, snowflake, etc.) needs to be narrower than the mouth of your jar.  I made one heart that, after it formed, was stuck in the jar!

I attached the heart to a string and the string to a pencil.  I measured so the heart hung in the center of the jar without touching the bottom or sides of the jar.  When the water started boiling, I took the heart out of the jar and added the water.  I stirred the solution until all of the Borax dissolved.  Next, I placed the heart in the jar.  I placed the jar in an area where it wouldn’t be disturbed.

First, the crystals formed on the bottom of the jar. It was really interesting to check it every so often and there were more and more crystals!  I left it overnight.  The next day, I took the heart out to dry and bring to class.  The entire heart was stacked with crystals!

At class, I had the large heart under the microscope for the kids to view. It turned out so sparkly and interesting to see.

I had each child create whatever shape they wanted to make. They also picked out their own Valentine’s Day pencil. I had the kids help to scoop the Borax into each jar. I made labels for the jars so I could tell whose was whose.  Next, I added water to the jars and attached the hearts to the pencils.

While I was putting the jars together, the kids wrote their findings in their journals. We talked about how the molecules of the Borax move a lot faster in the hot water and then slower and the solution cools down, forming the crystals. The kids got a kick out of this and acted out the molecules by running around and then standing really close together.

Each child took home their own jar. I hope that each one formed into beautiful crystals! I didn’t know how they were going to travel. I’ll find out next class! They came out so cute and we were able to see some crystals within the hour!

A few notes:

• I started experimenting with this project at home a week prior to when I was going to do it in class.  A little warning, the first time that I did it, it did not work.  I don’t know what I did wrong. The only thing that I could think of was that my main ingredient, Borax was too old.  The box that I was using was about two years old.  I am assuming this was the reason because next time, I used a new box of Borax and it worked!
• Doing this with a class of preschoolers was a lot of fun!  I wanted the kids to be able to create whatever shape that they wanted to.  However, this was very, very time consuming because then I needed to tie the string to the heart and pencil and measure it correctly.  If time is an issue, I would make the shapes at home and do the strings all of the same at home.  I ended up being very late for the next class.
• Two weeks later, I still have the large heart.  It is in really good shape, yet some of the crystals have fallen off.  I don’t know how long it will last.
• Here is a video from the St. Louis Science Center, with all of the steps.  They suggest using food coloring.  I will have to try that next time!

Enjoy!

~Miss Jenny