Mixing and Separating Solids

It is week number three and I have to admit that with each lesson I am definitely feeling more comfortable in my own skin in front of my scientist friends.  I really feel like Becky and I have provided a classroom science environment where the students feel comfortable sharing their ideas, taking risks, and asking questions. 

At the beginning of today’s lesson we let our friends know that we would need their help in answering the following science question:  “Does mixing 2 solids change their properties?”.   I asked the students to continually think about this question as we proceeded with the experiments.   We reviewed what we learned from last week and then went on to discuss what their definition of mixture was and asked for examples.  Becky was very helpful as she captured the students’ answers on the chart paper.

Becky then continued by reviewing the outline she wrote out on chart paper at the front of the class.  This was really instrumental in keeping the class on task and it served as a great reference for anyone who may have had questions on what they were supposed to be doing or what was next.  As Becky continued to review the instructions I distributed the summarized record sheet that Becky had put together.  This sheet was clear and simple and a great way to get the students to write down what they observed. She also educated our students about the process skill of observation and asked the students how they thought they might use this skill today. 

 I was very confident about the materials management portion of this lesson because I knew that Becky and I had fully prepared with the materials, outlines, handouts, and time management.  There were so many elements to this lesson that I couldn’t imagine being unprepared.  We worked in tam den to make sure that we were organized and ready to go.   

I then asked that one person from each pair retrieve their materials from the table near the sink.  I asked that no one start until everyone had their materials and all eyes were on me.    We proceeded to put the gravel and the salt on black paper and observe the materials with our lenses.  I modeled this step as Becky walked around to see if students needed help.  Becky then asked the students to predict and record what would happen if they mixed the two.  They mixed the solids and I stepped in to ask the students to predict and record how the mixture might change if the solids were separated.  The students then created their own sieves after watching me model how to make one.  We all separated the materials and recorded what we observed.  We asked the class to share their ideas and they were eager to do so.

An unexpected misconception by some of the students that did surface toward the end of this lesson was that the solids had indeed changed.  After a longer than expected discussion on this matter, Becky was quick on her feet and asked the students if the gravel was still gravel and if the salt was still salt.  I immediately saw the light bulbs going off and I hoped that they finally understood that the properties did not change.  I would know the answer in a moment when I revisited our science question from the beginning of class.

At the conclusion of our lesson I hesitantly asked if mixing two solids changed their properties.    There answer was like music to my ears….No, they responded the properties did not change. 

I wanted to jump for joy because after all that blood, sweat, and tears we knew they understood.  Yay!  We also remembered to ask them how they used the science process skill of observation today and again they knew the answer.  The students then finished up by writing and drawing what they observed in their journals.  Becky and I proceeded to work together with the students to clean up the room and collect all of their written work.   At the very end, I was sweating and my mouth completely dry but overall it felt like a complete success!