First to explain what each of these reactions are, for exothermic reactions to take place is when you combine your two products and the reaction is hot like crystallization of sodium acetate trihydrate, and for endothermic reactions you combine your two products and your reaction is cold like vinegar and baking soda.
For this objective I found the best way to provide an example of each to students would be through experiments; for endothermic I would use the vinegar and baking soda experiment and for the exothermic I would use the crystallization of sodium acetate trihydrate. To set this lesson up not only will the students be seeing this experiment, but they will use a tool called the Conceptual Change Model. The students will follow this model step by step as the experiment goes on. They will use the CCM for both experiments.
The intended learners for this could be any age group to use this tool but in this case the intended learners are 5th graders. To start each experiment the students will first see what materials and chemicals we will be using and from that they will make a prediction of what they think will happen. I will guide their predictions some sort, like asking if they think the temperature will change, will it become colder? Warmer? After the students have done this, as a class, they will share their predictions, this way they are able to see if other students think the similar to them or they will be able to see what other students will think will happen. As a class we will list all the predictions. Then as a class do the experiment. As the experiment is being tested the students will write down what is going on. After this they will go back to their original prediction and indicate whether their predictions was correct or not, why or why not. We will also discuss this as a class. Then as a group we will connect this experiment and findings to everyday life, what does it remind us of, have we ever seen this before? Like a volcano for example. Then have the students further their understanding by asking questions like if we changed any factors in this experiment would the results be the same. For the tool itself saftey is not an issue but when doing it along with experiments you must use the classroom saftey guidelines like wearing protective eye wear.
The CCM completely covers this objective, it not only through the experiments, shows the students an example of each exothermic and endothermic reactions but the CCM takes it one step further and has the students predict, experiment, and analyze what happens when you see these examples.
I find this tool to be extremely effective, not only does the class have a structured way to do these experiments but this tool helps students confront their misconceptions if they have any. Through experimental learning students have a hands on chance to see what they reason to be right is actually correct and can visualize why it is or not. The students also benefit talking about it as a class because they can then see how their fellow classmates think, they may think alike or completely different. The most effective part of this tool is how the students will connect the experiment to everyday life. It is important for them to see how science affects everyday life, and the reasons behind way things happen. This tool can help guide the students through this process.
The cost of this tool is somewhat cheap the Conceptual Change Model, the book that was written for, Targeting Students’ Physical Science Misconceptions Using the Conceptual Change Model by Joseph I. Stephans, is $32.95 so not too bad for you to use when using this tool the book also has activities you can do to help with the CCM.
I would defiantly use this tool in my classroom. Joseph Stephans main focus behind this book and the CCM is “learning stops when the answer is given”. That is why I will use this tool because I feel that it does a great job helping students discover their misconceptions in science and they can actually learn why instead of just getting the answer.
The weaknesses of this tool is that it requires class participation which can be hard to get from all students all the time. So when using this tool you have to always keep this in mind. Another is that for some students this structured style of teaching may be difficult for them to grasp so you may have to help accomidate for that.
| CCM Steps | Remarks/Narrative |
|---|---|
| 1.Make a prediction | Commit |
| 2.Discuss your predictions with your group. Come to a consenseus and reason behind it. | Expose |
| 3.Testing and discussing | Confront |
| 4.Resloving conflict between your predictions and the results | Accomodate |
| 5.Make connections to everyday life | Extend |
| 6.Go Beyond! | Questions you still have |