Each year I am truly excited when my honors classes are ready to learn the Quantum Mechanical Model (QMM) because this lesson was a crucial reason why I decided to become a chemistry major when I was in high school. I have always been in love with the periodicity of the elements and how clean and organized it all seems. Each year I have introduced the content from a different angle, each time hoping for better results and clearer understanding from the students (and each time secretly hoping to entice a new chemistry major!). And, unfortunately, each year I have confused students with the abundance of information that comes along with this model. This year was different. I created my own POGIL-inspired activity and let the activity do my heavy lifting.
My students completed this activity in three 44 minutes classes.
Provide students with activity document to be completed.
First, let me provide a little background on my choice of questioning strategies. In POGIL activities students are navigated through the learning cycle where they first explore a model (such as a graph, data, pictures, etc.) and then invent a concept or explanation for trends they have identified. Next, students apply their new ideas to additional examples and models to test their new ideas. The cycle can continue various rounds throughout one POGIL activity. The first questions should be short, easy questions that are found within the model itself. This allows students to slowly unpack what the model is representing and allows the students to gain confidence with the model. Then questions can begin to elicit prior knowledge and start them on the journey to identifying patterns and finding explanations. In an introductory lesson, the questions shouldn’t be overwhelming, requiring more than 2-3 models at a time, an overabundance of practice problems of the same nature, or requiring concepts that may burn the students out too quickly. Think of each question as small tiny steps in sequence to generate a larger picture.
Now, let me explain how I used the activity in class. Students worked in teams of four (with roles such as manager, reader, recorder, and analyst) to complete the activity. At stop signs, the manager would raise their hand to call me over to check their progress. During that check I am looking to make sure they aren’t proceeding through the rest of the activity with obvious misconceptions and I often ask follow up questions about the work they have done so far. If questions are answered incorrectly, we work back through those questions and I ask more questions about the models and their prior knowledge so they can rephrase their answers (I am sure not to give away answers myself). I believe one of the reasons the POGIL activities work so well for me is that I am transparent with my students. I tell them the exact reason why we use POGIL practices and the importance of teamwork and other process skills that are elicited as well as the importance of roles in uniting the team’s efforts.
My students had no prior knowledge about QMM before this activity with the exception of seeing relevant Photoelectric Spectra and identifying patterns that exist as the PES are compared (See my previous activity on ChemEdX titled “Introducing the Quantum Mechanical Model Using Photoelectron Spectroscopy”). But this was not our first POGIL activity in the class. Students have experienced the use of teams and roles in other lessons. The students were engaged throughout the lesson. This entire activity took us three separate 44 minute classes to complete. Each period was on a different day and we would start the period reviewing what we learned from the prior section. At the end of the activity my students took a quiz as a team with their notes out to see if they had learned and could translate the material to new elements. The team quiz was very successful and also required the students to reflect on their work as a team (student reflection can be a great way to identify positives and negatives of their team work in order to improve working in POGIL teams in the future). We followed this lesson and team quiz with some more practice and with an individual quiz as well. This was the smoothest introduction to QMM I have had in years!
Feel free to use and amend these handouts and please reach out if you have ideas or corrections! These activities only get better with the chemistry teacher hive mind! Note: Log into your ChemEd X account to access the Teacher Document. (Don't have one? Teachers can register for FREE!)
Prepare documents for distribution to students.
For more information about POGIL, please visit www.POGIL.org
Preview image: File:Periodic Table 2.svg. (2020, October 28). Wikimedia Commons, the free media repository. Retrieved 21:03, January 3, 2022 from https://commons.wikimedia.org/w/index.php?title=File:Periodic_Table_2.svg&oldid=504812504.
NGSS
Students that demonstrate understanding can develop models to illustrate the changes in the composition of the nucleus of the atom and the energy released during the processes of fission, fusion, and radioactive decay.
*More information about all DCI for HS-PS1 can be found at https://www.nextgenscience.org/dci-arrangement/hs-ps1-matter-and-its-interactions and further resources at https://www.nextgenscience.org.
Students that demonstrate understanding can develop models to illustrate the changes in the composition of the nucleus of the atom and the energy released during the processes of fission, fusion, and radioactive decay.
Assessment does not include quantitative calculation of energy released. Assessment is limited to alpha, beta, and gamma radioactive decays.
Emphasis is on simple qualitative models, such as pictures or diagrams, and on the scale of energy released in nuclear processes relative to other kinds of transformations.