Monday, April 21, 2014

Wright On Time: Arizona - Cave structure experiment

I had stumbled onto a series of books written about a homeschooling family and their adventures.  The Wright on Time book series explores a different state in each book.  We began reading the Arizona book and the Wright's cave adventure. 

I love that the book has a built in glossary for the children.  I would read aloud and ask if they knew what a highlighted term meant.  We looked it up and then Googled the term to learn more.  This piqued their interest in many different things within the story.  We learned about different minerals and gems.  We also learned about cave formations.

I wanted to show the children how slow stalagmites and stalactites took to form.  I found an experiment for us to do.

We gathered two glass jars, Epsom salt, spoons, string, screws, paper plate, and hot water.

We filled the glass jars half full of hot water and added Epsom salt to make a super saturated solution.  It took 8 tablespoons of salt per jar.

Next, we measured the string and tied the screws to each end.  The screws were used as weights to keep the string submerged. 

We placed the string in one jar to wet it thoroughly.  Then we stretched the string out.  One end was kept in the jar and the other end was placed in the other jar.

We put a paper plate under the stretched out string.  The salt solution would travel up the string and then form a drip.  The salt would start to crystalize and make a stalactite and the the remaining drip started the development of a stalagmite.

The children checked on the experiment every time they walked into the kitchen.  After several hours, a small stalactite began to form.  After a few days, we had a nice little stalactite and small stalagmite.  This gave the children a new appreciation of the large structures in caves.