A Crystal Snowflake Science Lesson December 07 2009
This science lesson plan about snowflakes doesn't depend on the weather. These crystal snowflakes can be created at any time of the year!
Focus and Materials
I've used this science experiment during our study of rocks as well as a fun experiment to do during the dreary winter months. This particular Crystal Snowflake science lesson focuses on supersaturation and how crystals are formed.
To have kids complete the experiment, you'll need a variety of wide-mouthed jars - the deeper, the better. The extra depth will give the snowflake more room to dangle and collect crystals. Ask for donations from parents, suggesting they clean out any empty jars they might have, such as spaghetti or jelly jars.
The rest of the materials are pretty easy to find, including the 20 Mule Team Borax Laundry Booster, which is found in the grocery store in the laundry soap aisle. I found that one standard-sized box was plenty for a classroom of crystal snowflakes, and it's inexpensive.
The Scientific Method
Whenever I approach science experiments with my kids, I always focus on teaching the Scientific Method. In our school district, we have to have a sample of a completed science experiment, and I've found that a passing sample takes a few tries. Teaching the Scientific Method gives elementary kids a solid foundation and helps them practice in order to complete a passing science worksample.
Question - Photocopy the Snowflake Science Lesson worksheet for each student. Go over it with them, reading through the procedure (the rest of the scientific method is blank). Lead them in a discussion of what they think the question of this experiment is, write a few suggestions down, and decide on a final question together. Explain that the point of the experiment is to have our question answered.
Hypothesis - In the context of the Question, what do your students think will happen in the course of the experiment? If this is one of your students' first experiments, you may want to have a guess from the whole group that everyone writes down; otherwise, each person writes down what they think will happen.
Procedure - This section is already typed out for your students. There is boiling water in this experiment, and I used a few portable hot pots or the giant coffee maker from the school's staff room. The rule was that students could not fill their jars with the water - I was the only one allowed to do this step.
Results - There is a sketch box and a spot for sentences regarding what happened to the pipe cleaners after one night. Some snowflakes will be SUPERsaturated, and will stick to a glob of crystallized borax inside the jar. A little tugging will get them free.
Conclusion - Have students refer back to their Question - how was it answered? How does the Conclusion compare with the Hypothesis? I've found with this question that kids don't want to be "wrong," and will try to change their Question, Hypothesis or Conclusion so that they fit neatly. I explain throughout the experiment that science is not about "Right" or "Wrong" answers, but instead about trying and seeing what happens, and that's what makes it fun. Encourage your students to report their findings truthfully.
Next Question - I also explain that often good science experiments result in more questions than answers. One example is "What amount of borax will result in a crystal snowflake but not a whole bunch of crystallized gunk at the bottom?" This is my personal question, but the ones your students come up with will depend on how the experiment went - probably closer to "What would happen to the pipe cleaner snowflake if we used cold water instead of boiling water?"
After the science experiment is all done, collect the Snowflake Science Lesson worksheet and use them for a science grade and/or worksample while your students take their crystal snowflakes home to enjoy. I like to bribe a few students to come in during a recess and clean out the jars for me - there's no easy way to do it (if you find one though, please leave a comment!).