Separation Techniques: The Salt of the Classroom

Finally, the first day in the lab arrived, and my vow to intrigue the generally disengaged through inquiry commenced.  The first lab of the year is always a basic separation lab traditionally used to teach lab techniques such as measurement, filtration and evaporation, as well as percent error and percent composition.  The techniques were successfully taught, but the focus of the lab shone a new light… student led learning.

To start, I ditched the lab sheet and replaced it with a revised and abbreviated article from Made How (http://www.madehow.com/Volume-2/salt.html#ixzz3AAiJR9LS).  Also included were a challenge and an opportunity for the students to be led down a path of discovery.  Students first read the article about salt and ways to obtain it.  They were then given the following challenge: You have a scoop of beach sand mixture and need salt for food; how do you separate the salt from the sand and salt mixture; and how much salt can you produce from 50ml of sand?  Students were given the page number from the textbook that would give hints about setting up the filtration system, and with that they were ready to figure out how to conquer the challenge.  After reading, they mapped out their own ideas about how to proceed in the lab.  They used the reading assignments to guide their ideas.  Students shared their ideas with their shoulder buddy and their pod partners before sharing them with the class and me.

My new role was to guide them by responding with questions, answering their questions and approving their plans.  When the lab was complete, we used the data to learn about percent error and percent composition.  Because we were interested in real world applications, I introduced a problem with salt domes in our area of the country.  We extended our path of learning by exploring the problems being experienced because of the use of salt domes in Bayou Corne, LA.  The students found this very interesting, and it gave us an opportunity to consider ethical topics in science.

In the past, I would have given students the lab with the procedures.  We would not have researched salt or the salt domes.  Also, the students would not have had the opportunity to write and talk about their ideas for separating the mixture.  My new commitment to inquiry makes me step back and ask what students can learn for themselves if I guide them and give them the opportunity.  It really is not that hard, it just requires a different way of thinking during the planning stage.

I am proud to say the first two and a half weeks were free of dreamers (sleepers), thinkers (daydreaming doodlers), and readers (of novels that is)... movers (pencil tappers) and shakers (attitude filled lip smackers)... and the captive student who feels imprisoned by me, the giver of knowledge and key-holder of the lab.  Instead, we were all engaged in the constructed path of inquiry!  We are on the road to deeper understanding through inquiry, the salt of the classroom.