Oxidation Argumentation Activity

When implementing NGSS standards, the science and engineering  practice of argumentation can be seamlessly implemented through the use of formative assessment probes. Paige Keeley’s NSTA press books are phenomenal resources of probes that can be used for a variety of topics. The probing statement/question provides a picture or scenario and potential answers. I facilitate a working group of chemistry teachers in the New York area and we recently created our own activity surrounding the topic of oxidation. The goal of the probe was to force students to think about what the meaning of oxidation is, as well as to allow students to engage in the science and engineering practice of argumentation. This was an introductory lesson to my oxidation and reduction unit prior to students learning the terms oxidation and reduction.

The following is the initial probe that was provided to students.

On the wall were the letters a, b and c, each on a large piece of paper. Students were asked to read the probe and to place a yellow sticky note for the first choice, a blue sticky note for the second choice, and green sticky note on the wall to show their prediction. The wall provided a nice visual to me, as the teacher, of my students’ preconceptions on the topic.

The students then met as a group in the designated areas with other classmates that shared the same first choice of Post-It color, meaning the same idea of what the term oxidation means. I assigned all the students who chose choice “a” to meet in one area of the room with a large white board. Those students in favor of choice “b” met in the opposite corner with a white board, the “c”s in another and a fourth group was created as an overflow group because by group “a” was initially most of the class. As a group, students came up with two points to support the groups’ argument that rationalized their choice. A group member wrote down the groups’ rationale on a large whiteboard and a spokesperson reported out.

Next aluminum foil was added to an aqueous solution of copper(II) chloride. Students were asked to write down their observations to the demonstration. They then were given the following probe and asked to describe their thinking and provide an explanation for their answer.

Students again met in the designated areas of the room with a group that best fit their choice. Students provided additional information to support their argument on the original whiteboard at their locations. Students who no longer agreed with the original argument were free to move to another group that better fit their view. A spokesperson reported out for each group.

A final probe was provided to students:

Students were again asked to describe their thinking and provide an explanation for their response. Students again found a group that best fit their answer to the probe and added more points to support the groups’ argument. Again, students who no longer agreed with the argument were free to move to another group that better fit their view. A spokesperson reported out key points for each group. Each student also recorded their own argument on their student handout.

Following the activity the students wrote a reflection on Microsoft Teams (you can use Google Classroom or paper version here as well) on how the process of argumentation allowed them to reason their final answer comparing the original Post-It choice to their final choice. Many students reflected on the need to develop a systematic approach to determine when oxidation was occuring. This provided a great introction to the need for oxidation numbers, a great segway into my next lesson. I found students less likely to complain about learning oxidation numbers than years past since they saw a need and purpose for them prior to learning about them in a lesson.

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