The Many Mixtures of Lesson 5!!

I cannot believe how fast time is going and that we are more than half way through our science unit on changes of matter!  This week's lesson dealt with mixing three different solids with water: gravel, toilet tissue, and salt.  As the lessons progress in this unit, they seem to get more complex, with more materials and more steps.  Lesson 5 definitely takes the cake with the amount of planning and preparation that was necessary.  I am so glad that my partner Kathy and I work so well together to make sure that we are prepared each week.

We started the lesson with a review of last week, and once again, the students impressed me with their quick and accurate answer of last week's science question.  We presented the new science question to guide the lesson: Do all solids behave the same when mixed with water?  Kathy had a great idea to create a science word wall that included the content vocabulary for the changes unit.  We already had several words with pictures and definitions from prior lessons on the poster.

This week we introduced two new science vocabulary words: dissolve and solution.  As I was preparing this section, I was having trouble describing dissolve in a simple, clear sentence appropriate for third graders.  I decided to rely on my biggest resource: my mom, who is one of the best teachers out there and teaches students who have a hearing loss.  She showed me the sign language for dissolve, which demonstrated the meaning of dissolve a lot clearer than describing it in words. The students were very receptive to using sign language to define dissolve!  A few students used the sign throughout the lesson, and the whole class remembered the sign at the end of the lesson.  We also addressed an important misconception involving the process of dissolving.  One student said that when something dissolves, it disappears.  We made sure to point out that just because we cannot see the dissolved solid, does not mean that it's not there.

The next vocabulary word was solution, another difficult concept.  We decided to use the example of lemonade as a solution, which the students were able to relate to.  We asked them if you drink lemonade, do you get one sip of just water, one sip of pure sugar, and one sip of lemon?  They all responded with a "no way, you get a mouthful of the same mixture with each sip"!  I definitely think it is helpful to point out key vocabulary so that students understand the concepts during the experiment, but also so they can begin to use these science words themselves.

Kathy then reviewed the process skill from last week and introduced this week's process skill of recording data.  Kathy had another great idea to use the process skill posters that our professor gave us.  The students really liked these pictures, and they served as a visual reminder of the skill we were focussing on.  We then went over the steps (which were pretty complicated) and the safety (which are students are experts at now).  Next, we dove into the experiment!  The students first examined their solids.  Then they mixed the solids with water, observed the mixture, stirred the mixture, and observed again.  Kathy gathered the students on the rug to discuss the results of the experiment, which was a good change of setting for the students.  Kathy addressed another misconception at this point, pointing out that the tissue broke into small particles, but they did not actually dissolve.  I ended the lesson by asking the science question of the day, to which they all responded, "no, all solids do not behave the same way when mixed with water"!  We also let them know that they will be trying to separate the mixtures next week.  Overall, the flow of the lesson was very natural, well balanced, and effective.  Preparation, materials management, time management, and team work have a lot to do with a successful lesson flow.  With all the detailed instructions, we do have to make sure we are not spending too much time going over the steps and get the students engaged in the experiment soon after the start of the lesson.  I am really enjoying teaching science!  Although it is a lot of preparation, it is worth every bit and is the most authentic learning environment we, as future teachers, could ask for.