I organized the learning goals into course-level systems thinking and climate justice learning goals, and more traditional chemistry-specific learning goals that accompany each of the 21 case studies that I describe in the "Description and Teaching Materials" section. You can choose to use only one of these case studies in your chemistry course, or many of them, or all of them. In order to accommodate these choices, I have organized the learning goals by case study. If you decide to use a sub-set of the case studies, you can assess some or all of the course-level learning goals to guide the development of your teaching materials to support chemistry education focused on systems thinking and/or climate justice. Climate justice refers to the disproportionate effects of climate disruption and fossil fuel extraction and processing activities on marginalized groups and future generations. Systems thinking is important for understanding the connections between chemistry and climate justice.

Course-Level Systems Thinking and Climate Justice Learning Goals

These learning goals are not necessarily specific to any one case study, but instead define the overarching systems-thinking and climate- justice learning goals for my entire course. I do not assess these learning goals as part of every case study, mostly due to time limitations, and because no single case study is designed to support every goal. I assess these learning goals using pre-post surveys¹ and pre-post case-study analyses¹, which students complete at the start of the course and at the end of the course. I strive to support these learning goals with my teaching materials in a cumulative way, as a result of students' exposure to many systems-thinking and climate-justice case studies over the 11-week-long General Chemistry course.

1. Identify the chemical and physical forms of a compound or element in a real-world system.
2. Explain how an element or compound dissolves in water using charge-based interactions.
3. Explain how to determine the chemical forms of a compound or element using the periodic table and/or the octet rule.
4. Explain how to determine the physical form of a compound or element using their melting and boiling points and temperature data about the environment in which they exist.
5. Identify social, political, moral, environmental, health, and economic challenges in a real-world case study.
6. Identify who is most impacted by a climate-justice issue and explain how they are impacted.
7. Propose ways that those most impacted could address the climate injustice they face.
8. Build a critical consciousness toward understanding the systemic nature of climate injustice.
9. Recognize that STEM can be used as a tool to address climate injustice.
10. Recognize that climate change will disproportionately impact marginalized groups.

Case Study 1: Climate Impacts and Air Pollution in Mongolia

1. Recognize how polluting chemicals produced by fossil fuel burning in the atmosphere creates climate injustices for certain human populations.
2. Gain knowledge of and apply key chemistry concepts crucial to systems thinking in chemistry, particularly with regard to understanding local and global systemic issues related to climate change and air pollution.
3. Use knowledge of chemistry concepts to discuss atmospheric pollution and related climate injustice with family and friends (civic engagement).
4. Identify ways that local communities experiencing climate injustice can address the challenges they are facing.
5. Build science literacy and science communication skills through a civic-engagement assignment.

Case Study 2: Carbon Emissions and Inequity

1. Determine the number of significant figures in an answer that results from addition, subtraction, multiplication, and/or division.
2. Write a conversion factor to express a relationship between two quantities.
3. Use conversion factors to solve single-step and multi-step problems.
4. Convert gram to mole, and vice versa, using molar mass.
5. Convert mole to number of molecules using Avogadro's number.
6. Use a number written in scientific notation in multiplication, division, addition, and subtraction.

Case Study 3: Fracking for Methane Gas, Part 1

1. Explain how to determine the physical form of a compound or element using their melting and boiling points and temperature data about the environment in which they exist.
2. Find information about melting and boiling points using credible online sources.
3. Explain how to determine the chemical forms of a compound or element using the periodic table and/or the octet rule.

Case Study 4: Inequity From Energy-Matter Interactions

1. Articulate that the destruction of the ozone layer is not directly caused by climate change.

Case Study 5: Natives Lands and a Just Transition to Renewable Energy

1. Describe how electrons move to higher energy levels when they absorb energy and fall to lower energy levels when they release energy.
2. Explain how quantum energy levels apply to quantum dot solar cells.

Case Study 6: Chemical Elements for Clean Energy

1. Write the electron configuration for a chemical element and identify the valence electrons.
2. Draw an orbital diagram for a chemical element and identify the valence electrons.
3. Identify valid sets of quantum numbers.
4. Draw connections among electron configurations, orbital diagrams, and quantum numbers.
5. Reflect on how communities are disproportionately affected by transition metal mining and on what they can do as STEM students or professionals to promote a just transition to clean energy.

Case Study 7: Electric Vehicle Batteries and Lithium Mining on Paiute and Shoshone Lands

1. Identify the chemical and physical forms of a compound or element in a real-world system.

Case Study 8:Fracking for Methane Gas, Part 2

1. Identify the chemical and physical forms of a compound or element in a real-world system.
2. Explain how to determine the chemical forms of a compound or element using the periodic table and/or the octet rule.

Case Study 9: Molecular Polarity and Human Health in Sacrifice Zones

1. Apply molecular polarity and bond strength to real-world contexts, specifically how chemicals in the environment disproportionately affect marginalized communities. 
2. Describe how chemical pollutants impact human health and how they are regulated or unregulated by the United States government.
3. Propose ways that those most impacted by pollutant-related health outcomes could address the climate injustice they face.
4. Determine the number of valence electrons involved in the molecule using the periodic table. 
5. Draw Lewis dot structures using the octet rule and consider exceptions to the octet rule.
6. Determine electron geometry and bond angle(s) based on the number of electron groups.
7. Determine molecular geometry based on the number of bonds and lone pairs.
8. Draw molecules to show their molecular geometry.
9. Determine molecular polarity using molecular geometry and the polarity of bonds in the molecule.
10. Determine how central atoms in a molecule hybridize based on the number of electron groups.
11. Assign a formal charge to each atom in a molecule and use them to determine the most likely resonance form.  
12. Explain molecular interactions based on their polarity and the "like dissolves like" rule.

Case Study 10: Hidden Polarity in Greenhouse Gases

1. Identify two reasons that nonpolar greenhouse gas molecules (e.g., CO₂, CH₄) warm the Earth.

Case Study 11: Direct Air Capture of CO₂: To Do or Not To Do?

1. Reflect on the ethics and safety of geoengineering as a way to address the climate crisis.
2. Identify the chemical and physical forms of a compound or element in a real-world system.

Case Study 12: Fossil Fuels Companies, Stranded Assets, Water Protectors, and Pipelines

1. Write a balanced chemical equation for a combustion reaction.
2. Solve multi-step real-world stoichiometry problems using chemistry skills and critical thinking.

Case Study 13: PM 2.5 Formation Through Chemical Reaction

1. Solve limiting reactant word problems to calculate the theoretical yield of a product.  
2. Solve multi-step real-world stoichiometry problems using chemistry skills and critical thinking.

Case Study 14: Disproportionate Impacts and Stoichiometry of Smog 

1. Write a balanced chemical equation from a qualitative description of a chemical reaction.
2. Apply stoichiometry to real-world problems that involve more than one chemical reaction.
3. Solve limiting reactant word problems to calculate the theoretical yield of a product. 
4. Identify and calculate the amount of excess reactant remaining after a chemical reaction.

Case Study 15: Visualizing Charge-Based Interactions in Direct Air Capture (DAC) Aqueous Solutions

1. Identify full and partial charges on the solutes and the solvent in an aqueous solution.
2. Identify the solutes and the solvent in an aqueous solution.
3. Sketch the charge-based interactions among solutes and the solvent in an aqueous solution.

Case Study 16: Using the Dilution Equation to Estimate Benzene Contamination of Drinking Water from Fracking

1. Calculate solute concentration in an aqueous solution using the dilution equation (M₁V₂=M₂V₂).
2. Recognize that concentrations must have the same units if you want to compare them.

Case Study 17: Precipitation Reactions and Solubility Rules for Ionic Compounds: Direct Air Capture

1. Apply the solubility rules for ionic compounds to predict precipitation in an aqueous solution.
2. Predict the ions dissolved in an aqueous solution when ionic compounds or acids are present.

Case Study 18: Redox Chemistry, Green Hydrogen, and Displacement of Indigenous People

1. Describe the direction of electron transfer among reactants in an oxidation-reduction reaction.
2. Identify the oxidized and reduced reactants in an oxidation-reduction reaction.

Case Study 19: Redox Chemistry and Lung Damage from Air Pollution

1. Describe the direction of electron transfer among reactants in an oxidation-reduction reaction.
2. Identify the oxidized and reduced reactants in an oxidation-reduction reaction.

Case Study 20: Nuclear Energy: Should It Stay or Should It Go? 

1. Reflect on the ethics and safety of nuclear energy as a way to address the climate crisis.
2. Identify the chemical and physical forms of a compound or element in a real-world system.

Case Study 21: Water Contamination, Food Production, and Human Health in the San Joaquin Valley, California, USA

1. Identify the chemical and physical forms of a compound or element in a real-world system.
2. Explain how an element or compound dissolves in water using charge-based interactions.
3. Explain how to determine the chemical forms of a compound or element using the periodic table and/or the octet rule.
4. Explain how to determine the physical form of a compound or element using their melting and boiling points and temperature data about the environment in which they exist.

I use the case studies described in this activity during the first 11-week-long quarter (term) of a three-quarter year-long General Chemistry series taught at my two-year college. The class size is 48 students, who meet for two 1-hour and 50-minute class sessions each week synchronously on Zoom. That group of students is split into two smaller groups of 24 students each, which meet for one 2-hour and 50-minute laboratory session each week. The time required for each case study varies widely, ranging from five minutes for the shortest case studies to 120 minutes for the longest one. Although I teach a hybrid course, with class sessions on Zoom and laboratory sessions in-person, the climate-justice case studies described in this activity could easily be implemented in an in-person or asynchronous version of a similar course. The course covers atomic structure, molecular structure and polarity, stoichiometry, aqueous solutions, periodic law, bonding, molecular orbital theory, radioactivity, and several types of reactions (combustion, precipitation, acid-base, gas evolution, and oxidation-reduction). I thread climate-justice and systems-thinking case studies through most of these topics. Each case study requires students to have mastered different skills or concepts prior to encountering it, and I describe what is required for each case study below. I use Chapters 1 through 8, and Chapter 20, of Nivaldo Tro's Chemistry: Structure and Properties (2nd Edition) textbook to support the chemistry content, but any General Chemistry textbook (or no textbook at all) will work for implementing these activities. The case studies are mostly independent of each other, so you could use them in a different order than described here, or you could use only a subset of them. Whether using one case study or a few, or all, I recommend including positive stories of change whenever possible, so that students are exposed to empowerment and hope and are less likely to feel despair and apathy as a result of learning about climate injustice.

I use a free online classroom polling application (Nearpod) to solicit student responses during in-person laboratory sessions and Zoom polls during the 1-hour and 50-minute class sessions, but it is not necessary to use these specific polling applications. (For example, you could ask students to raise their hands to verbally respond, write on a piece of paper, do a "think-pair-share" or some other means of soliciting student responses.) Students can access both of these applications for free and answer multiple-choice or type open-ended responses on their smartphones or laptops. I use the polls because they are anonymous and open to everyone, and I find it helps collect responses from more reserved students and/or the class as a whole. You need access to an internet connection to show online videos used in some case studies. I also use a mix of printed handouts and the Canvas online Learning Management System (LMS) to distribute assignments and collect student work, but any LMS will work and is not necessary, as you could instead print out handouts, activities, and polling questions for distribution to students during class. The activity can also be adapted for similar but larger chemistry courses at a four-year college or university, with some case studies best completed during smaller weekly breakout, discussion, and/or laboratory sessions with the support of a graduate teaching assistant. The case studies could also be used in a secondary school chemistry course or in other college-level chemistry courses (e.g., an introductory chemistry course for students not majoring in a STEM field, such as "Chemistry in Society" or a GOB - General, Organic, and Biological Chemistry - course taken by students pursuing careers in the health sciences).

Each case study below is focused on a climate-justice issue. Climate justice is centered on taking action for a just transition to a sustainable future by recognizing the disproportionate effects of climate disruption on marginalized groups and future generations. It includes not only the impacts of climate change (e.g., more flooding, hurricanes, droughts, wildfires, wildfire smoke), but also how fossil fuel extraction and processing, renewable energy technologies, and geoengineering affect these groups. For the case studies below, I provide a series of activities, polls, handouts, and slide decks. Many of the case studies contain elements of systems thinking and almost all include an equity ethic, which are important for understanding connections between chemistry and climate justice as well as increasing participation of typically marginalized students in STEM. Systems thinking in chemistry asks students to apply chemistry knowledge and skills to real-world systems. During the first quarter of General Chemistry, I focus on students' analysis of the chemical forms (neutral atom, charged ion, ionic compound, molecule) and physical forms (solid, liquid, gas, dissolved) of chemicals in a real-world system. Case Studies 3, 7, 8, 20, and 21 have an explicit focus on these. (I recognized the importance of students learning to identify chemical and physical forms of matter from a systems thinking assessment published by Vicente Talanquer, which I applied and adapted to my course by observing my own students' struggles to identify chemical and physical forms in real-world systems.) The Equity Ethic is a phrase coined by Ebony McGee and Lydia Bentley (2017) in a journal article in which they refer to students' "principled concern for social justice" (page 4, The Equity Ethic: Black and Latinx College Students Reengineering Their STEM Careers toward Justice). The Equity Ethic ties to the disproportionate effects of climate disruption on marginalized groups and future generations. It explains why a social justice-centered approach to STEM teaching can be more appealing to groups typically marginalized in STEM, particularly students of color and women. When these students see that STEM can be used to help their communities, then they are more likely to pursue a STEM major, stay in a STEM major, or end up in a STEM career. (Case studies 1 and 9 also include small civic engagement components, but this is more a focus for a quarter-long air pollution research-based laboratory curriculum that I use in this class, alongside these case studies; I plan to publish this laboratory curriculum on this site, and a web link to it will be provided here soon.)

General Instructor Preparation: Check online video links, prepare classroom presentations, set up polling questions (I use Nearpod for in-person and Zoom polls for synchronous remote learning), prepare handouts to print out for in-person meetings or to upload to an online LMS (I use Canvas) for remote instruction

Case Study 1: Climate Impacts and Air Pollution in Mongolia (1 hour).

1. Recognize how polluting chemicals produced by fossil fuel burning in the atmosphere creates climate injustices for certain human populations.
2. Gain knowledge of and apply key chemistry concepts crucial to systems thinking in chemistry, particularly as relevant to understanding local and global systemic issues related to climate change and air pollution.
3. Use knowledge of chemistry concepts to discuss atmospheric pollution and related climate injustice with family and friends (civic engagement).
4. Identify ways that local people and communities experiencing climate injustice can address the challenges they are facing.
5. Build science literacy and science communication skills through a civic-engagement assignment.

How I assess Case Study 1 Learning Goals: I have already published this case study as a separate Activity in this database, so I direct the reader there for details about how I assess the learning goals: Systems Thinking and Civic Engagement for Climate Justice in General Chemistry: CO₂and PM 2.5 Pollution from Coal Combustion

Course-level learning goal(s) targeted: 1, 5, 6, 7, 8, 9, 10

Case Study Description. This activity has a system-thinking focus. I use one hour of a laboratory session, during the first week of the 11-week-long quarter, to implement it. I have already published this as a separate Activity in this database, and direct the reader there for details: Systems Thinking and Civic Engagement for Climate Justice in General Chemistry: CO₂ and PM 2.5 Pollution from Coal Combustion. This case study provides students with an introduction to systems thinking in chemistry, as well as a quarter-long air pollution research project that I integrate into the laboratory sessions of the course, during which students use handheld monitors to measure CO₂ and PM 2.5. (The curriculum for this quarter-long air pollution research-based General Chemistry laboratory curriculum will be published on this site soon and a web link provided here.)

Case Study 2: Carbon Emissions and Inequity (50 minutes).

1. Determine the number of significant figures in an answer that results from addition, subtraction, multiplication and/or division.
2. Write a conversion factor to express a relationship between two quantities.
3. Use conversion factors to solve single-step and multi-step problems.
4. Convert gram to mole, and vice versa, using molar mass.
5. Convert mole to number of molecules using Avogadro's number.
6. Use a number written in scientific notation in multiplication, division, addition, and subtraction.

How I assess Case Study 2 Learning Goals: Case Study 2 Learning Goals Assessment.docx (Microsoft Word 2007 (.docx) 24kB Sep20 24)

Course-level learning goal(s) targeted: 5, 6, 7, 8, 9, 10

Case Study Description. I use this activity during a Zoom class session during the first week of the quarter as a "warm-up" review of the quantitative chemistry concepts and skills that students are expected to have mastered prior to taking General Chemistry. I ask students to work on the activity quietly on their own, but encourage them to ask lots of questions and ask me to go over parts of the problems when they get stuck, so that I am actively engaging with students during their work time. For this activity, students practice and review how to solve quantitative problems that have several parts, as well as units, dimensional analysis, unit conversion, significant figures in calculations, molar mass, metric conversation, and Avogadro's number. The climate justice issue central to the activity is inequities in carbon emissions by countries of the Global North (United States, Europe, Canada, Australia, New Zealand, Japan, and Israel), which have emitted a much higher amount of CO₂ to the atmosphere and hold more responsibility for climate breakdown, as compared to the lower-emitting countries of the Global South (the rest of Asia, Africa, and the rest of the Americas), who have done little or nothing to cause climate change (historically) but have experienced a disproportionate share of climate-related damages. Students use dimensional analysis to calculate the amount of compensation owed by countries of the Global North to countries of the Global South, using CO₂ emissions data derived from a graphic in Who has contributed most to global CO₂ emissions?. Students convert grams, moles, and molecules of CO₂ to kilotonnes and review the rules for carrying significant figures through calculations.

Warm-Up Activity - Emission & Inequity.docx (Microsoft Word 2007 (.docx) 292kB May22 24)

Case Study 3: Fracking for Methane Gas, Part 1 (1 hour).

1. Explain how to determine the physical form of a compound or element using their melting and boiling points and temperature data about the environment in which they exist.
2. Find information about melting and boiling points using credible online sources.
3. Explain how to determine the chemical forms of a compound or element using the periodic table and/or the octet rule.

How I assess Case Study 3 Learning Goals: Case Study 3 Learning Goals Assessment.docx (Microsoft Word 2007 (.docx) 22kB Nov20 24)

Course-level learning goal(s) targeted: 1, 3, 4, 9

Case Study Description. This case study is the first of a two-part case study¹, to which I return in the sixth week of the quarter (see Case Study 8). Part 1 of this case study involves 30 to 45 minutes of work for students on an assignment prior to class and then 15 to 20 minutes during class for the activity. I teach the classroom part of this activity during a laboratory session in the second week of the quarter. The assignment is a case study focused on drinking-water contamination experienced by farming communities in rural Pennsylvania, USA, where intensive fracking for methane (so-called "natural gas") is occurring. Students read a short (4 to 5 paragraph) case study, accompanied by a graphic to help them visualize how fracking chemicals can interact with groundwater and drinking water, and then they answer a series of questions. The questions ask students to identify all the physical forms (solid, liquid, gas, dissolved) and chemical forms (atom, ion, molecule, ionic compound) that could possibly be present for elements or compounds in the real-world fracking system described in the case study. Students explain how they determined physical and chemical forms using charge-based interactions for dissolved substances, the octet/duet rule for determining possible chemical forms, and environmental temperatures with melting and boiling points for determining possible physical forms (solid, liquid, gas). Because the assignment is meant to assess students' skill level for identifying the physical and chemical forms in real-world systems at the beginning of the quarter, before we have covered this content in the course, I tell students that they are not expected to know how to answer every question and that their grade for the assignment will be based on effort only. I ask them not to spend more than 30 to 45 minutes on this assignment and tell them that they do not need to do extensive research to find answers.

During the laboratory session, I ask students to explain to me how they know the physical and chemical forms of matter could be present in the real-world fracking system, given only the element or compound and environmental temperatures. I use open-ended questions to solicit their explanations, which I set up before class using the polling application in Nearpod. I skim through their responses and provide feedback and information to the class about how to determine chemical and physical forms. For physical forms, I tell students to look up the melting point and boiling point of a chemical using a database (e.g., PubChem) and to compare those to the environmental temperatures of a real-world fracking system. For this case study, the range of temperatures to which chemicals can be exposed in a Pennsylvania fracking system are given. For chemical forms, I present a flow diagram (Slide 6 of PowerPoint) to help them determine chemical forms in the fracking case study (I use CH₄ to illustrate how to use the flow diagram). (The flow diagram is a simplification that targets the chemical forms covered in the first quarter of my General Chemistry course and there are always exceptions to these guidelines.) I also review information covered the previous week in a lecture, regarding how to predict if you have a molecule (all nonmetal elements) or an ionic compound (metal + nonmetal elements). (Again, this is a simplification and a generalization because there are always exceptions in chemistry, but it does hold most of the time and helps students make predictions about chemicals in real-world systems.) I conclude the activity by emphasizing when neutral atoms will be found in environmental systems. Students struggle with this and think atoms are present much more often than they actually are, even though more elements are not stable on their own because their valence shells do not have an octet as neutral atoms. I explain to students that in the vast majority of cases, in real-world systems at the temperature and pressure of the Earth's surface, chemical elements will be present as ions, ionic compounds, and/or molecules but not as non-bonded neutral atoms. I point out exceptions to this in the periodic table (e.g., noble gases; see Slide 8 of PowerPoint). I do a call-and-response about atoms (Slide 9), as a way to reinforce this, because students struggle with this all quarter and I bring the call-and-response back into the classroom or into other interactions with students, as needed.

Fracking Case Study Assignment.docx (Microsoft Word 2007 (.docx) 26kB May22 24)

Fracking Systems Thinking Questions.pptx (PowerPoint 2007 (.pptx) 940kB May25 24)

Case Study 4: Inequity From Energy-Matter Interactions (15 to 20 minutes).

1. Articulate that the destruction of the ozone layer is not directly caused by climate change.

How I assess the Case Study 4 Learning Goal: Case Study 4 Learning Goal Assessment.docx (Microsoft Word 2007 (.docx) 21kB Sep20 24)

Course-level learning goal(s) targeted: 5, 6, 8, 9, 10

Case Study Description. I use this case study during a Zoom class session in the second week of the quarter, when students learn about electromagnetic radiation (e.g., wavelength, frequency, amplitude) and the electromagnetic spectrum, and how visible light interacts with matter (e.g., visible light reflection creates color, white light passing through a prism). I use eight PowerPoint slides to structure this case study, which can be inserted into a lecture focused on these topics to connect them to climate justice and technology-based solutions (e.g., white roofs to reflect sunlight and keep buildings cooler) without taking up too much class time. Real-world applications like these are not included in most General Chemistry textbooks, so the slide deck provided here is a way to engage students by connecting chemistry to tangible and meaningful issues for students. I provide text in the notes section of some slides that describes each slide in more detail. I begin this case study by highlighting ways that energy from the electromagnetic spectrum interacts with matter to protect us from harmful radiation (i.e., stratospheric O₃ interacts with UV-C and UV-B), to cause climate change (i.e., CO₂ and tropospheric O₃ interact with infrared radiation) and air pollution (i.e., O₃ and particulate matter produced by chemical reactions mediate by UV light), and to contribute to solutions to global heating with "cool roofing" (i.e., painting roofs white to reflect sunlight) and "millimeter waves" used in geothermal energy production (Slides 1 and 2). On Slide 2, I use a Zoom polling question (see "Inequity Energy-Matter Interactions Polling Question.docx" below) to ask students whether destruction of the ozone layer is caused by climate change, in order to address a common misconception about climate change. It is not caused by climate change and I use the left-hand graphic on Slide 2 to explain how the ozone layer is in the upper atmosphere and is caused by CFCs, not CO₂ or other greenhouse gases. I also provide students with a web link to a PhET simulation to help them visualize what happens when molecules in the atmosphere interact with different types of radiation (e.g., CO₂, CH₄, H₂O, NO₂, and O₃ which are greenhouse gases and interact with infrared radiation, while O₂, N₂, and CO are not greenhouse gases and do not). I return to this interaction between greenhouse gases and infrared energy later in the course, to introduce the idea of the "hidden" polarity in molecules that results from their vibrational motion when students learn about molecular polarity (see Case Study 10). On Slide 4, I present climate injustices related to the energy-matter interactions I explained on Slide 2 using a 2021 report written by the United States Environmental Protection Agency (US EPA), called Climate Change and Social Vulnerability in the United States: A Focus on Six Impacts, which predicts the vulnerability of different groups of people in the U.S. to future climate impacts (low income, minority, no high school diploma, 65 and older). After presenting the report, I offer students information about the disproportionate impacts of sea level rise on people of color and low income people living in the southeastern U.S. (the Carolinas, Miami; aligns with "Coastal Flooding and Traffic" section of the EPA report) and extreme heat on women living in Indian slums (aligns with "Extreme Temperature and Health" section of the EPA report, but focus shifts to a country of the Global South not included in the EPA report). At the end of the slide deck, I present technologies that use some of the chemistry topics we are covering: how visible light interacts with matter (e.g., painting roofs white to reflect sunlight) and how "millimeter waves" (explained in the Grist video How a breakthrough in geothermal could change our energy grid) are being used in geothermal energy production. I do not spend too much time in Slide 5 through 8 and instead use the content on the slides as a means to offer examples of how climate-justice issues, and some technologies that can address these issues, are relevant to the chemistry we are studying. I provide resources on each slide that students can explore in more detail, if they wish.

Inequity Energy-Matter Interactions.pptx (PowerPoint 2007 (.pptx) 3.8MB Sep16 24)

Inequity Energy-Matter Interactions Polling Question.docx (Microsoft Word 2007 (.docx) 13kB Jun19 24)

Case Study 5: Natives Lands and A Just Transition to Renewable Energy (5 to 10 minutes).

1. Describe how electrons move to higher energy levels when they absorb energy and fall to lower energy levels when they release energy.
2. Explain how quantum energy levels apply to quantum dot solar cells.

How I assess Case Study 5 Learning Goals: Case Study 5 Learning Goals Assessment.docx (Microsoft Word 2007 (.docx) 21kB Sep20 24)

Course-level learning goal(s) targeted: 5, 6, 9, 10

Case Study Description. I use this case study during a Zoom class session in the third week of the quarter when students learn about quantum objects, Bohr model of the atom, and energy absorption/release as electrons move among different energy levels in an atom. The case study is focused on the impact of renewable energy technologies on Native lands, as well as a technology (i.e., quantum dots solar cells) that aligns with the content we are covering. This case study works well during this section of the course, which contains fairly abstract content that can be difficult to connect to real-world issues (notations and terminology to describe energy levels in atoms, which I call "the language of chemistry"; e.g., the four quantum numbers n, l, m_l, and m_s, probability density and radial distribution functions, and electron configurations and orbital diagrams). The case study is a fairly quick "interlude" that involves five PowerPoint slides (below) that can be inserted into a lecture on these topics to demonstrate the application of the Bohr model and energy absorption/release as electrons move among different energy levels. In the PowerPoint, I provide text in the notes section of each slide that describes in more detail what I explain to students. I begin with a few examples of renewable energy projects being sited on Native lands in the U.S. and how this degrades and destroys cultural and religious sites. I offer a definition of "just transition" by the Climate Justice Alliance for students who are interested in exploring this more on their own outside class time. I then explain how quantum dot solar cells could help with a more just clean-energy transition (at least in terms of the amount of land required) and draw analogies between energy absorption/release in a quantum dot and an atom (which they just learned about) to explain how these solar cells work. I show the first two minutes of Color by Size: Quantum Dots to help students visualize how quantum dots work. The video focuses on color on television screens, but these ideas transfer to quantum dot solar cells. After the video, I use a Zoom poll to check students' understanding of how electrons move to higher energy levels when they absorb energy and fall down to lower energy levels when they release energy, within the context of a quantum dot solar cell application (which have conductance and valence bands as the higher and lower energy levels, respectively, instead of the numbered "n" levels for atomic orbitals in their textbook). I end the case study with Slides 4 and 5, which provide students with an example of how people have used their quantum-chemistry education to promote renewable energy technologies (Slide 4) and democracy by protecting votes during elections (Slide 5). I do not spend more than 1 to 2 minutes on Slides 4 and 5 and instead quickly share these examples and provide students with links to a TEDx talk (Turning CO₂ into oil: Lisa Dyson at TEDxFulbright) and a PBS video (Quantum Physics to Protect Votes) if they would like to learn more on their own. (PBS is the Public Broadcasting Service in the United States.)

Native Land Just Transition Renewable Energy.pptx (PowerPoint 2007 (.pptx) 1.3MB Sep18 24)

Quantum Dots & Just Transition Polling Question.docx (Microsoft Word 2007 (.docx) 14kB Sep16 24)

Case Study 6: Chemical Elements for Clean Energy (30 to 60 minutes).

1. Write the electron configuration for a chemical element and identify the valence electrons.
2. Draw an orbital diagram for a chemical element and identify the valence electrons.
3. Identify valid sets of quantum numbers.
4. Draw connections among electron configurations, orbital diagrams, and quantum numbers.
5. Reflect on how communities are disproportionately affected by transition metal mining and on what they can do as STEM students or professionals to promote a just transition to clean energy.

How I assess Case Study 6 Learning Goals: Case Study 6 Learning Goals Assessment.docx (Microsoft Word 2007 (.docx) 24kB Sep20 24)

Course-level learning goal(s) targeted: 5, 6, 9, 10

Case Study Description. This is a synthesis activity that I use during a Zoom class session in the fourth week of the quarter, after students learn to identify valid sets of quantum numbers (n, l, m_l, m_s), write electron configurations, and draw orbital diagrams. This activity helps students make connections among these seemingly disparate concepts and skills. I ask students to work on the activity quietly on their own, but encourage them to ask lots of questions and ask me to go over parts of the problems when they get stuck, so that I am actively engaging with students during their work time. In my experience, the amount of time it takes for students to complete the activity varies greatly. The activity focuses on nine different chemical elements (Li, Ni, Si, Ce, Gd, Al, Ti, Sc, Sb) needed for a clean energy transition (e.g., electric vehicles, solar photovoltaic plants, wind farms). I selected these elements to provide a wide range of examples for students to practice writing electron configurations, drawing orbital diagrams, and identifying valence electrons for Part A of the activity (from different blocks in the periodic table; e.g., s block, p block, d block, and f block), not based on the importance of each chemical element in the clean energy transition (although all are involved, and I provide references for more information in the document). Students also practice determining valid sets of quantum numbers for Part A, but this is not tied to any specific element. Part B is focused on helping students draw connections among quantum numbers, electron configurations, and orbital diagrams. Finally, Part C asks students to think about connections to societal issues. They scan an article, The Energy Transition Will Need More Rare Earth Elements – Can We Secure Them Sustainably?, and choose a chemical element they want to focus on. They again use electron configurations, orbital diagrams, and valence electrons, and connect these to quantum numbers. After this, they think about climate justice issues that might arise as related to the element they chose. They watch a four-minute-long video, Myanmar bears the cost of green energy, to reflect on how some communities are disproportionately affected by the mining of chemical elements needed for a clean energy transition and on what they can do (now or in the future), as a future STEM professional, to ensure the clean energy transition is just and equitable.

Chemical Elements & Clean Energy Transition.docx (Microsoft Word 2007 (.docx) 120kB Jun4 24)

Case Study 7: Electric Vehicle Batteries and Lithium Mining on Paiute and Shoshone Lands (15 to 20 minutes).

1. Identify the chemical and physical forms of a compound or element in a real-world system.

How I assess the Case Study 7 Learning Goal: Case Study 7 Learning Goal Assessment.docx (Microsoft Word 2007 (.docx) 21kB Sep20 24)

Course-level learning goal(s) targeted: 1, 3, 5, 6, 7, 8, 9, 10

Case Study Description. I use this case study during a Zoom class session during the fifth week of the quarter when students are beginning to learn about bonding, which begins with ionic bonding in my course. The case study has a systems-thinking focus and is short (I provide one slide for the case study, below, which you can insert into a PowerPoint presentation). The case study focuses on mostly inorganic chemicals (e.g., Li₂CO₃) or metals (e.g., Li, Ni, Co, Cu, Al) or compounds with polyatomic ions (e.g., H₂SO₄), all of which can be part of compounds that are ionically bonded, so it aligns well with ions and the ionic bonding chemistry content. Two videos introduce this activity. Before the students watch them, I share the chemical formulas or element symbol for the chemicals they will hear about as they watch. Students watch the first 7.5 minutes of a video Lithium mine pits electric cars against sacred Indigenous land, which describes the impact of lithium mining on the sacred lands and burial sites of the Paiute and Shoshone tribes near Thacker Pass in the state of Nevada (USA), and then about two minutes (from 5:13 – 7:23) of Can you recycle an old EV battery?, which provides some great visuals of what happens with different chemical elements during the recycling of lithium-ion batteries. These videos explain how the demand for lithium (Li), for use in lithium-ion batteries in electric vehicles (EV), is higher than ever, along with many other chemical elements needed for these batteries (e.g., Li, Ni, Co, Cu, Al). Mining activities for minerals that contain these elements have increased in the United States and, in some places, are affecting Native people and their lands. However, there is hope that mining will not have to occur at a large scale, as there are companies working to figure out how to create EV batteries that can be recycled; for example, Li-cycle is a company featured in the second video. Following the videos, I use a three-question multiple-choice class poll that asks students to identify the possible chemical forms for lithium carbonate (Li₂CO₃), for the elements mentioned in the recycling video (Li, Ni, Co, Cu, and Al), and for sulfuric acid (H₂SO₄, which was mentioned as a harmful mining waste). The choices for each question are molecules, ions (charged particles, positive or negative), atoms (neutral particles, no charge), and/or ionic compounds. As I review students' answers to each poll question and share the results of the poll with students, I explain how to predict all the possible chemical forms that can exist for a given chemical element or compound (see flow diagram on Slide 6 of "Fracking Systems Thinking Questions.pptx" PowerPoint file under Step 3). When the poll is complete, I provide students with two additional video resources that they can watch on their own to learn more about ways that chemistry contributes to recycling EV batteries to recover Lithium and other chemical elements needed for a clean energy transition (The value of recycling lithium ion batteries and the process and Li-Cycle is a Canadian company working on Li ion battery recycling).

EV Batteries Lithium Mining Paiute Shoshone Lands.pptx (PowerPoint 2007 (.pptx) 201kB Jun19 24)

EV Li Mining Paiute Shoshone Lands Polling Questions.docx (Microsoft Word 2007 (.docx) 14kB Jun19 24)

Case Study 8: Fracking for Methane Gas, Part 2 (10 minutes).

1. Identify the chemical and physical forms of a compound or element in a real-world system.
2. Explain how to determine the chemical forms of a compound or element using the periodic table and/or the octet rule.

How I assess Case Study 8 Learning Goals: Case Study 8 Learning Goals Assessment.docx (Microsoft Word 2007 (.docx) 21kB Sep20 24)

Course-level learning goal(s) targeted: 1, 3

Case Study Description. This is Part 2 of the fracking case study (see Case Study 3 above for Part 1) and I use it during a Zoom class session that occurs during the sixth week of the quarter when students are beginning to learn about electron sharing in molecules (to form covalent bonds), Lewis dot structures, and the octet rule. Part 2 of the case study involves two polling questions and often a little bit of discussion with the class. (In addition to the polling questions, I provide two PowerPoint slides that you can insert into a presentation.) It also has a systems-thinking focus, which asks students to identify all possible physical (solid, liquid, gas, dissolved) and chemical (atom, ion, molecule, ionic compound) forms of elements and compounds present in a real-world fracking system. In order to explain why different physical and chemical forms exist, students need to learn about (1) charge-based interactions for dissolved substances, (2) the octet/duet rule for determining possible chemical forms, and (3) environmental temperatures with melting and boiling points for determining possible physical forms. At this point in the quarter, they have learned about (3) and will learn (1) later in the quarter during the solution-chemistry part of the course. For this case study, students will learn (2), which is focused on how to use the octet/duet rule to determine possible chemical forms.

I start by explaining that the octet/duet rule can be applied to main group elements (i.e., these elements will tend to have eight electrons in their valence shells) and that these elements will donate, receive, and/or share electrons in order to get an octet/duet in their valence shells. (At this point, students have not learned about expanded octets or other exceptions to the octet rule, which is covered during the next week of the quarter, so I exclude this information for now.) I use bromine to illustrate how you can use the octet rule to predict possible chemical forms (atom, ion, molecule, ionic compound). Bromine is a nice example because you can use the octet/duet rule to predict that it could occur in three of the four chemical forms (ion, molecule, ionic compound), depending on where it is present in the system. It is important to note that, when bromine is mentioned in the news or in popular magazine articles, and sometimes even in scientific papers, the chemical form is not specified and it is referred to only as "bromine" (e.g., in a BBC article Who's afraid of bromine?, a person interviewed for the article states that "The Dead Sea has the highest concentration in the world of bromine," but this could be referring to either bromide as an ion (Br^-) or the molecule (Br₂) dissolved in the water, which is often referred to as "elemental bromine." It is very confusing for students!) This illustrates the importance of students learning to use the octet rule to predict chemical form.

After explaining the octet rule, I use a Zoom poll with two multiple-choice questions that ask students to identify the chemical forms of bromine that could be present in the fracking system and to explain how they know, using the octet rule. I remind students of the data about ions in groundwater and drinking water, which was presented during the initial case study (see Case Study 3), because they will need this information to infer that bromine can form bonds with other elements present in the system. The multiple-choice options for the first question are molecules, ions (charged particles, positive or negative), atoms (neutral particles, no charge), and/or ionic compounds. I ask students to choose all that could be possible in a real-world fracking system. The multiple-choice options for the second question asks students to think about how they can explain each chemical form using the octet/duet rule, by thinking through how the number of valence electrons is influenced by ion formation (choice b and c), ionic bonding (choice d and e), or covalent bonding (choice f) as well as the number of valence electrons in a neutral bromine atom (choice a). For choice f, students have just learned that nonmetals like bromine can share electrons to form covalent bonds to satisfy the octet rule, so they usually get this one easily. For ion formation (choice b and c) and ionic bonding (choice d and e), I add choices for the presence of ions or compounds in water or air. Students have already learned that halogens like bromine can form ions. They also know that electrons are transferred during ionic bonding (learned the previous week) and can deduce that bromine (as a nonmetal receiving electrons) will get an octet when an electron is transferred to it from another element it bonds with. However, students grapple with the presence of bromine ions and bromine-containing ionic compounds in air (choices c and e) and water (choices b and d), which gives me a chance to share that these chemical forms for bromine will most likely be present (stable) in water due to charge-based interactions in aqueous solutions and will not be commonly present in air (where they are unstable). ("Stable" and "unstable" are defined here with reference to the range of temperatures and pressures typical of the Earth's surface or near-surface.) Sometimes the "why" behind this has to wait until we cover aqueous solutions in two weeks, but many students with a strong background in chemistry already know this. Others don't realize that ions are only present in water at the temperatures and pressures of real-world aqueous systems. As I am explaining all of this, I present the flow diagram again (Slide 2 of PowerPoint) to illustrate how to use it to predict the chemical forms of bromine. I end with the flow diagram to give another example of how to use it even though, at this point, I want students to start gaining a process-based understanding of chemical forms (e.g., octet/duet rule) rather than blindly following the flow diagram. Even with a process-based understanding, the flow diagram still proves to be a useful tool that helps scaffold students' thinking.

Fracking and the Octet Rule.pptx (PowerPoint 2007 (.pptx) 88kB Sep16 24)

Fracking and the Octet Rule Polling Questions.docx (Microsoft Word 2007 (.docx) 14kB Jun19 24)

Case Study 9: Molecular Polarity and Human Health in Sacrifice Zones (60 to 120 minutes).

1. Apply molecular polarity and bond strength to real-world contexts, specifically how chemicals in the environment disproportionately affect marginalized communities. 
2. Describe how chemical pollutants impact human health and how they are regulated or unregulated by the United States government.
3. Propose ways that those most impacted by pollutant-related health outcomes could address the climate injustice they face.
4. Determine the number of valence electrons involved in the molecule using the periodic table. 
5. Draw Lewis dot structures using the octet rule and considering exceptions to the octet rule.
6. Determine electron geometry and bond angle(s) based on the number of electron groups.
7. Determine molecular geometry based on the number of bonds and lone pairs.
8. Draw molecules to show their molecular geometry.
9. Determine molecular polarity using molecular geometry and the polarity of bonds in the molecule.
10. Determine how central atoms in a molecule hybridize based on the number of electron groups.
11. Assign a formal charge to each atom in a molecule and use them to determine most likely resonance form.
12. Explain molecular interactions based on their polarity and the "like dissolves like" rule.

How I assess Case Study 9 Learning Goals: Case Study 9 Learning Goals Assessment.docx (Microsoft Word 2007 (.docx) 24kB Nov20 24)

Course-level learning goal(s) targeted: 5, 6, 7, 8, 9, 10

Case Study Description. I use this case study during a laboratory session that occurs during the seventh week of the quarter. During this session, students watch a documentary (The Sacrifice Zone) and build molecules using plastic model kits to determine their molecular polarity. You can reduce the amount of class time needed for this case study by asking students to watch the documentary prior to class, as it is 32 minutes long. In addition to molecular polarity, a central chemistry concept in this case study is "like dissolves like," which can explain why some carcinogens bioaccumulate in the fatty tissues of the human body and others do not. The molecules in the case study also provide real-world examples of how bond length and bond order affect the reactivity of molecules. Prior to the laboratory session, students read or listen to Poisons in the Air written by ProPublica and answer multiple-choice questions (see "Regulation of Chemicals in Sacrifice Zones.docx" below) about what they read that calls their attention to different carcinogenic pollutants in the air, the human health affects illustrated through stories of affected families and communities, and how the United States Environmental Protection Agency (U.S. EPA) and U.S. federal laws (e.g., Clean Air Act) regulate (or do not regulate) these chemicals. I also use the article to build the case for why citizens need to be civically engaged and to highlight an example of an organization for which STEM professionals work (ProPublica). ProPublica created an interactive map of Sacrifice Zones in the U.S. to help citizens understand environmental risks by making air pollution data from U.S. EPA's Toxic Release Inventory more accessible to non-scientists. Reading (or listening to) the article and answering the questions takes students 30 to 60 minutes. I set up the multiple-choice questions as a quiz in Canvas, so that questions are automatically graded and summarized as "quiz statistics" for the class as a whole. This allows me to view the results prior to the laboratory session to see how they did. I encourage students to read through the questions before they read the article, so that they know what information to look for, and I tell them that the questions mostly follow along with the order in which the article presents the information. These suggestions make their completion of the assignment as focused and efficient as possible.

During the laboratory session, I use the "Molecular Polarity and Sacrifice Zones.pptx" PowerPoint to structure the session. I present the case study at the start of the laboratory session. It takes about 60 minutes of class time to present the documentary and the PowerPoint material.   I start by presenting students with a set of questions that I would like them to think about and take notes on as they watch the documentary (Slide 2 of PowerPoint). I provide these questions as a handout during class, where they can take notes (see "The Sacrifice Zone Documentary Handout.docx" below). Next, in the PowerPoint, I focus on civic engagement, which is meant to scaffold students toward presenting the results of their quarter-long air pollution research project to a relevant community outside the classroom at the end of the quarter. (I will publish this quarter-long research-based laboratory curriculum here soon and a web link here at that time). I begin by building the case for why we need all people to be civically engaged by explaining what the U.S. EPA does (and does not) do when it comes to air pollution. I do this using one of the questions that students answered before class (Slide 3). Next, I highlight how ProPublica, a public advocacy organization who wrote the "Poisons in the Air" article that they read, helps citizens understand environmental risks by making air pollution data from U.S. EPA's Toxic Release Inventory more accessible to non-scientists. I note that it is STEM professionals working for ProPublica that do this work (Slide 4). This provides students with an example of a career where STEM professionals can be advocates for sacrifice-zone communities disproportionately affected by air pollution. Finally, just before showing the documentary, I call students' attention to a list of civic and community engagement ideas on the back of their handout (Slide 6), which they can use to help them answer the third question on the handout as they watch the documentary.  Also, before starting the documentary, I remind students of the three questions I would like them to answer while watching (Slide 6). The documentary can be purchased from Talking Eyes media and viewing options are on their How to Watch web page. It is unfortunate that this documentary is not freely available, but it is made by a small production company working to highlight the stories of marginalized communities. It is very engaging and inspiring for students, so I feel it is worth obtaining the documentary. Immediately following the documentary, I spend one or two minutes sharing a positive story of change with students. The most recent story I shared is this article published in April 2023 by the nonprofit newsroom Grist: EPA announces rules curbing cancer-causing pollution from chemical plants. I strive to find up-to-date news when possible, such as from news sources that embody "solutions-focused journalism" (e.g., Grist, Inside Climate News, Yale Climate Connetions). After this, I spend 5 to 10 minutes (Slides 8 through 12) reviewing the concept of "like dissolves like"; introducing persistent organic pollutants (POPs) mentioned in the Poisons in the Air article (benzene), the documentary (dioxin) and one other (PFBA); using bond length and bond strength to explain (in part) why these molecules break down slowly in the environment and in our bodies through chemical reaction (hence the label "persistent"); and explaining how all human bodies (regardless of a person's weight) contain fatty adipose tissue that contain nonpolar molecules that POPs interact with strongly due to their similar polarity ("like dissolved like"). For the remainder of the laboratory session (1 hr and 50 minutes), students build molecules with plastic model kits to determine their polarity. This is a standard type of laboratory assignment for most college-level General Chemistry courses in the U.S., which I have modified to focus on molecules that are relevant to carbon dioxide and other greenhouse gas emissions as well as other air pollutants. (See "Molecular Polarity Lab.docx" below for my full laboratory assignment.) Near the end of this laboratory assignment (see page 8), once students have had a lot of supported practice determining the polarity of molecules, I ask them to explain the polarity of a few POPs as well as a fatty acid molecule similar to those found in the adipose tissue of the human body. Then they use the concept of "like dissolves like" to explain why these molecules interact with each other so strongly.

If you find this case study on sacrifice zones compelling and your students find it engaging, you can expand it into a quarter-long project for a General Chemistry course, an introductory chemistry course (e.g., Chemistry in Society), and/or a non-STEM majors introductory chemistry class taken by students pursuing careers in the health sciences (General, Organic, and Biological Chemistry). Mandana Ehsanipour at North Seattle College in Seattle, Washington, USA created a quarter-long project from this case study that can be used in all of these chemistry courses and published it on this site: Research Project on Pollutants in Sacrifice Zones for Chemistry Courses: The Role of Industry, Governments, Local Communities, and Scientists.     

Regulation of Chemicals in Sacrifice Zones.docx (Microsoft Word 2007 (.docx) 25kB Sep5 24)

Molecular Polarity and Sacrifice Zones.pptx (PowerPoint 2007 (.pptx) 1.6MB Sep5 24)

The Sacrifice Zone Documentary Handout.docx (Microsoft Word 2007 (.docx) 23kB Sep5 24)

Molecular Shape and Polarity Laboratory Assignment.docx (Microsoft Word 2007 (.docx) 148kB Sep5 24)

Case Study 10: Hidden Polarity in Greenhouse Gases (10 to 15 minutes).

1. Identify two reasons that nonpolar greenhouse gas molecules (e.g., CO₂, CH₄) warm the Earth.

How I assess the Case Study 10 Learning Goal: Case Study 10 Learning Goal Assessment.docx (Microsoft Word 2007 (.docx) 21kB Sep20 24)

Course-level learning goal(s) targeted: 6, 10

Case Study Description. I use this case study during a Zoom class session during the seventh week of the quarter near the end of the section of my course where students learn about molecular polarity. I use eight PowerPoint slides and two short videos to structure this case study. (See "Greenhouse Gases and Hidden Polarity.pptx" below.) At this point, students know how to determine the polarity of a molecule using molecular shape and bond polarities. To add to this, I introduce the idea of "hidden polarity" in molecules, which results from their motion (vibrational motion, specifically). I begin this case study by taking two or three minutes to share a few recent news stories focused on how people working in certain professions (e.g., farmer workers, construction, cooks) are disproportionately impacted by dangerous temperatures during the more frequent and intense heat waves of a changing climate: Workers Are Dying From Extreme Heat, Why Extreme Heat Is So Deadly For Workers, and Heat Waves Are Making Restaurant Kitchens Unsafe. I then ask the simple question "Why is planet Earth getting so hot?" and tell them that chemistry can explain. I begin the explanation by giving a quick overview of the three general types of molecular motion (vibrational, rotational, and translational) and showing students one minute (from 1:32 to 2:41 minutes) of a video Vibration of Molecules CHEM Study, which was made in the 1960s but is still a good one for helping students visualize how molecules move! This is especially important because the students spent a large amount of time during this week's laboratory session building stationary plastic models of molecules (see Case Study 9 above), which does not alert them to the fact that molecules are constantly moving. After presenting this video excerpt, I review the structure of two greenhouse gas molecules (CO₂ and CH₄) that they built during the laboratory session and note how they concluded during lab that these molecules are nonpolar, based on their geometry and bond polarities. Next, I show them a three-minute-long video How Do Greenhouse Gases Actually Work?, which shows how the vibrational motion of these and other greenhouse gases in the atmosphere creates a temporary ("hidden") molecular polarity that allows these molecules to interact with (absorb) infrared energy as it is leaving the atmosphere and hold that heat energy in the Earth's atmosphere. In addition to introducing polarity induced by vibrational motion, this case study provides a more in-depth explanation of topics explored in Case Study 4, in which students learned that energy from the electromagnetic spectrum interacts with matter to cause climate change, but with no further explanation as to how this interaction works. I use a multiple choice Zoom poll question to check their understanding. (See "Greenhouse Gas Hidden Polarity.docx" Word file below.) After the chemistry explanation, I quickly provide a little more information about the composition of air in the atmosphere, the identity of greenhouse gases other than CO₂ and CH₄ (many students do not realize there are others!), and the sources of these gases (Slides 5 through 7). Most students are not aware that greenhouse gases make up such a tiny percentage of all gases in the atmosphere, such that small changes in their amounts can make a big difference to global heating, nor are they aware of the impact and sources of greenhouse gases beyond CO₂ and CH₄ (e.g., NO₂ and fluorinated gases such as SF₆). To end this case study, I quickly share the article Biden Admin Unveils First-Ever Heat Protections For Workers to show students that the U.S. federal agency OSHA (Occupational Safety and Health Administration) is working on a rule that would protect workers from the heat.

Greenhouse Gases and Hidden Polarity.pptx (PowerPoint 2007 (.pptx) 3.2MB Sep6 24)

Greenhouse Gas Hidden Polarity Polling Questions.docx (Microsoft Word 2007 (.docx) 14kB Sep6 24)

Case Study 11: Direct Air Capture of CO₂: To Do or Not To Do? (40 to 70 minutes).

1. Reflect on the ethics and safety of geoengineering as a way to address the climate crisis.
2. Identify the chemical and physical forms of a compound or element in a real-world system.

How I assess Case Study 11 Learning Goals: Case Study 11 Learning Goals Assessment.docx (Microsoft Word 2007 (.docx) 21kB Sep20 24)

Course-level learning goal(s) targeted: 5, 6, 8, 9, 10

Case Study Description. This case study has a systems-thinking focus that allows students to practice identifying all the possible physical (solid, liquid, gas, dissolved) and chemical (atom, ion, molecule, ionic compound) forms of elements or compounds present in a real-world Direct Air Capture (DAC) system. This systems-thinking activity has a strong focus on the aqueous (dissolved) phase. The case study I present here is a small excerpt from a larger two-part DAC laboratory experiment that I created and use during the eight and tenth weeks of the quarter. (These laboratory experiments are part of a quarter-long research-based General Chemistry laboratory curriculum centered on air pollution that I will publish on this site soon and provide a web link to it here at that time). I include an excerpt from those laboratory experiments here as a short activity that can be used independently of these experiments when you are starting the aqueous-solution chemistry section of your course. I created this shorter activity for two reasons. First, the chemistry of DAC provides an excellent case study relevant to chemical reactions that occur in aqueous solution (e.g., precipitation and acid-base reactions). I return to this case study multiple times during both laboratory sessions and Zoom class sessions in order to illustrate and show applications of new chemistry concepts that students learn in the weeks following this activity. Second, and very importantly, most climate scientists are strong critics of DAC, arguing that it is too expensive, too energy intensive and polluting, a young technology not ready in time to meet climate goals, and generally a profit-driven distraction from reducing CO₂ emissions. A 2022 IPCC report calls for "immediate and deep emissions reductions across all sectors" of society as the primary focus of efforts to mitigate climate change, with all other measures "from planting trees to carbon capture technologies" (includes DAC) as "secondary to reducing our dependence on fossil fuels." (The IPCC is the Intergovernmental Panel on Climate Change is the United Nations body for assessing the science of climate change and has produced scientific assessment reports since 1990 that explain the global scientific consensus on climate change.) As a result of this controversy, the case study provides students with an excellent opportunity to think about the ethics of new technologies. As future STEM professionals, this type of question (in general) is important for students to have at the forefront of their minds as they embark on their STEM careers.

I use a PowerPoint presentation, a video, a Nearpod polling question, several articles, and an activity handout to structure the case study as well as provide students with a lot of extra resources they can explore to learn more about DAC (see below for PowerPoint, polling question, activity handout, and resource handout). I begin by showing students a 5-minute and 45-second-long video titled Should we pull carbon out of the air with trees, or machines?, which explains how much CO₂ must be removed from the atmosphere by the end of the century. It compares two (of many other) options for doing this: trees and DAC. The video does not clearly advocate for either option. Immediately following this video, I use a Nearpod poll to see what students think about DAC before they learn more about it by asking them: "Do you think that Direct Air Capture is an ethical and safe technology that should be used to address the climate crisis?" The purpose of this poll is to get a window into their initial thoughts, without knowing much about it! (Most student do not know much about it, although the number of students that do is quickly increasing with DAC being in the news more in recent years.) After the poll, I move through Slides 5 through 8 fairly quickly. I use these slides to provide students with an overview of the six major Negative Emissions Technologies (NETs) being considered (I use terminology and definitions from a 2019 National Academies of Science report), point out that chemistry plays a large role in two NETs (DAC and Accelerated Chemical Weathering of Rocks), show students an artist's rendition of what DAC systems might look like in the future, and tell them that the first commercial DAC facility in the U.S. opened in Tracy, California late in the year 2023. After this, I spend about 5 to 10 minutes presenting Slides 9 through 12 to provide an overview of the scientific consensus on DAC (according to the IPCC); the new tax incentives and policies being used to promote DAC in the U.S.; the strong criticisms (i.e., too expensive, too energy intensive and polluting, a young technology not ready in time to meet climate goals, profit-driven distraction from reducing CO₂ emissions); and a climate justice case study about a man who lost consciousness while driving along a road in Sataria, Mississippi, USA (a sacrifice zone, see Case Study 9) when a CO₂ pipeline ruptured nearby. I provide many resources where students can learn more about the information presented on these slides (see "DAC Resource Handout.docx" below) to help them think more about the ethics and safety of DAC. These resources are optional for students who wish to learn more outside class time. Finally, I spend about 5 to 10 minutes explaining the chemistry behind the specific hydroxide-based DAC technology that students will explore during the activity (as described by Baciocchi and colleagues in a 2006 issue of Chemical Engineering and Processing). I use Slides 14 and the "Direct Air Capture of Carbon Dioxide.docx" handout to prepare students for the activity, which takes them 15 to 30 minutes to complete. As part of the quarter-long research-based General Chemistry laboratory curriculum centered on air pollution, students read the 2019 journal article Life cycle carbon efficiency of Direct Air Capture systems with strong hydroxide sorbents for one of their "Journal Club" sessions in the ninth or tenth week of the quarter, in order to learn more about how much energy is needed to power DAC, how much CO₂ is emitted during DAC, and how much water and other resources are needed as well as pollution created. A big "take away" from this paper is that the electricity source (fossil fuels versus renewable energy sources) used to power DAC is the major factor that will determine whether there is a significant net removal of CO₂ from the atmosphere. After they read this paper, I re-poll them using the same question as I used at the beginning of this case study ("Do you think that Direct Air Capture is an ethical and safe technology that should be used to address the climate crisis?"). I see a shift in the percentage of students who view this as ethical and safe after they've had a chance to learn about it and reflect on it. As part of this re-polling, I share their initial response to this poll so that they can compare it with their response one to two weeks later. (I take a screenshot of their initial responses and save it to share the second time they take the poll.)

Direct Air Capture of Carbon Dioxide.pptx (PowerPoint 2007 (.pptx) 4.5MB Sep9 24)

Direct Air Capture Polling Question.docx (Microsoft Word 2007 (.docx) 13kB Sep6 24)

Direct Air Capture of Carbon Dioxide Handout.docx (Microsoft Word 2007 (.docx) 318kB Sep6 24)

DAC Resource Handout.docx (Microsoft Word 2007 (.docx) 18kB Sep9 24)

Case Study 12: Fossil Fuels Companies, Stranded Assets, Water Protectors, and Pipelines (15 to 20 minutes).

1. Write a balanced chemical equation for a combustion reaction.
2. Solve multi-step real-world stoichiometry problems using chemistry skills and critical thinking.

How I assess Case Study 12 Learning Goals: Case Study 12 Learning Goals Assessment.docx (Microsoft Word 2007 (.docx) 21kB Sep20 24)

Course-level learning goal(s) targeted: 5, 6, 7, 8, 10

Case Study Description. I use this case study during a Zoom class session when students begin learning about chemical reactions and stoichiometry during the eighth week of my quarter. The four PowerPoint slides that I use (below) can be inserted into an existing presentation covering these topics. The case study provides students with an example of how reaction stoichiometry can be applied to real-world problems. I start by showing two minutes (from 47:38 through 49:38 minutes) of a newscast by Democracy Now! titled "I'm Not a Criminal... Enbridge Is": Charges Tossed Against Winona LaDuke & Others for Pipeline Action. The video shows people protesting Enbridge's Line 3 tar-sands pipeline in Minnesota and describes the arrest of three indigenous activists. (Enbridge is a Canadian oil company who owns a pipeline that runs from Canada through Minnesota where it transports oil from tar sands, which are a "dirty" molasses-like type of oil with a high bitumen content.) After this video, I pose these questions to students: "Why Don't We Just Stop Using Fossil Fuels? Why Do We Continue, Despite the Protest and Activism?" I tell them that the people shown in the video, whose traditional tribal lands are in Minnesota where Line 3 exists, are Water Protectors and explain how they were trying to protect their water resources from the pipeline when they were arrested. I also provide a quick definition of tar sands. Next, I introduce stoichiometry by providing a definition and showing how it can be applied to determine how much more coal, gas, and oil the world can burn and still stay within the safe limit of 1.5 degrees Celsius of warming. (This was a target agreed upon in the Paris Agreement at the 21st Conference of the Parties, COP21, in 2015.) I spend some time on Slides 2 and 3 explaining what is shown in the Figure on that slide. I start by explaining the two orange bar graphs, which show the global "carbon budget," which is the amount of CO₂ that can still be emitted globally (in Gigatons of CO₂, Gt CO₂) to keep the Earth at 1.5 degrees Celsius (middle bar graph) and 2 degrees Celsius (right bar graph). Then I explain the bar graph labeled "Developed Reserves," which shows the amount of CO₂ that would be released to the atmosphere if we burned all the coal, gas, and oil reserves that have already been developed by fossil fuel companies and are essentially ready to extract. These are often referred to as "stranded assets" because fossil fuel companies have invested money in them and are fighting to make sure they get a return on their investment (ROI) by extracting and selling them. I point out to students that the amount of CO₂ in developed reserves is about twice what we can emit if we are to limit warming to 1.5 degrees Celsius. I also mention that fossil fuel companies receive a lot of subsidies from governments (worldwide) and that, in turn, companies help fund political campaigns. As a result, it is unlikely that governments will stop fossil fuel companies from extraction. I explain that this is why people resort to protest and activism, and risk arrest. After explaining the graph, I present a stoichiometry problem to calculate gallons of gasoline that would have been burned to cause the carbon budget to drop by 110 Gt CO₂ between 2018 and 2020 (you can see this drop in the Figures on Slide 4). To solve this problem, students write the balanced chemical equation for the combustion of gasoline, then solve the problem using the stoichiometric coefficients they came up with. I asked them two Zoom poll questions about balancing the chemical equation to make sure they have it correct before they try the problem (Questions 1 and 2 in "Fossil Fuel Stoichiometry Polling Questions.docx"). Prior to this problem, students know how to balance chemical equations, so this provides them with more practice. They also know about combustion reactions, such that when a chemical that contains C and H (C₈H₁₈, used to approximate gasoline) combusts, it reacts with oxygen gas to form CO₂ and H₂O. Students use dimensional analysis that includes the stoichiometric coefficients, the molar masses of CO₂ and C₈H₁₈, the density of C₈H₁₈, and a conversion from gallons to liters. Prior to this case study, students know how to use molar mass, density, and other types of simple conversions (e.g., gallons to liters) in a dimensional analysis. Although they know how to use all the conversion factors, many struggle to come up with an overall strategy for using them, so I ask a third Zoom poll question to help them break the problem into smaller steps (see Question 3 in "Fossil Fuel Stoichiometry Polling Questions.docx"). I often shorten the time needed to complete this problem, if necessary, by providing students with the balanced chemical equation as their starting point.

Fossil Fuel Stoichiometry Problem.pptx (PowerPoint 2007 (.pptx) 1.1MB Sep17 24)

Fossil Fuel Stoichiometry Polling Questions.docx (Microsoft Word 2007 (.docx) 14kB Sep17 24)

Case Study 13: PM 2.5 Formation Through Chemical Reaction (15 to 20 minutes).

1. Solve limiting reactant word problems to calculate the theoretical yield of a product.  
2. Solve multi-step real-world stoichiometry problems using chemistry skills and critical thinking.

How I assess Case Study 13 Learning Goals: Case Study 13 Learning Goals Assessment.docx (Microsoft Word 2007 (.docx) 21kB Sep20 24)

Course-level learning goal(s) targeted: 5, 6, 8, 9, 10

Case Study Description. This case study is a stoichiometry problem that involves limiting reactants. I use it during the same Zoom class session as Case Study 12 (eighth week of quarter), except I use this one at the end of the session after the limiting-reactants content (and sometimes ask students to complete the problem for practice before our next Zoom session if I run out of time). It is a more complicated problem than the one in Case Study 12 because it involves two balanced chemical equations instead of one (and also limiting reactants). In addition to providing a more complex example, I use this problem as scaffolding to prepare students for the activity in Case Study 14 (but you do not have to do Case Study 14 to implement this case study). I use five PowerPoint slides (below) to structure this case study, which can be inserted into an existing presentation covering these topics. This case study presents some of the chemical reactions that lead to the formation of PM 2.5 particles, which are pollutants emitted into the atmosphere during most types of combustion (e.g., forests during wildfires, gasoline in cars, coal-fired power plants, waste incinerators). I begin by describing a recent research study (2022) published in JAMA Internal Medicine titled Association of Particulate Matter Exposure With Lung Function and Mortality Among Patients With Fibrotic Interstitial Lung Disease. I also share with students a link to an article in The Daily Climate called Tiny particles of air pollution appear more deadly if from human-made sources, which explains this research study in language that is easier for the layperson to understand and highlights the part of the study that I focus on (the chemical composition of PM 2.5 particles). (JAMA is Journal of the American Medical Association.) Both of these resources describe how PM 2.5 particles that are rich in nitrates, sulfates, and ammonium are more harmful to human health. The Daily Climate article also describes how communities surrounding the most polluting facilities have higher rates of poverty, more people of color, and more people over the age of 65, making them more vulnerable to PM 2.5 pollution. Next, I show students images that show how PM 2.5 particles are made up of a lot of different chemicals (including nitrates, sulfates, and ammonium) and the different sources and pathways by which these different types of PM 2.5 form, according to a Nature Chemistry article (2020) The complex chemical effects of COVID-19 shutdowns on air quality. I then show them the two general chemical reactions that lead to the formation of NH₄NO₃-rich PM 2.5 (which I represent as NH₄NO₃ only in the balanced chemical equations, ignoring any other chemicals in the PM 2.5 particle to simplify the word problem). I use a Zoom poll with two questions (below) to ask them how they should approach the problem before they start working on it. The questions help them break the problem into two steps and come up with a strategy for solving it, before they start plugging numbers into their calculator without much thought (which many of them tend to do!). Once they have a plan, most can quickly do the calculations. This Zoom poll also forces students to grapple with the new jargon introduced in this section of the course: limiting reactant, reactant in excess, actual yield, percent yield (the quantity they calculate for both steps of the problem is the theoretical yield, so you can highlight that too!).

Chemical Reaction & PM 2.5 Formation.pptx (PowerPoint 2007 (.pptx) 716kB Sep9 24)

Chemical Reaction PM 2.5 Polling Questions.docx (Microsoft Word 2007 (.docx) 14kB Sep9 24)

Case Study 14: Disproportionate Impacts and Stoichiometry of Smog (20 to 40 minutes). 

1. Write a balanced chemical equation from a qualitative description of a chemical reaction.
2. Apply stoichiometry to real-world problems that involve more than one chemical reaction.
3. Solve limiting reactant word problems to calculate the theoretical yield of a product. 
4. Identify and calculate the amount of excess reactant remaining after a chemical reaction.

How I assess Case Study 14 Learning Goals: Case Study 14 Learning Goals Assessment.docx (Microsoft Word 2007 (.docx) 23kB Nov20 24)

Course-level learning goal(s) targeted: 5, 6, 8, 10

Case Study Description. I use this as an activity toward the end of the stoichiometry and reaction chemistry unit, as a synthesis of the many concepts covered. This usually occurs at the beginning of the ninth week of the quarter. I structure this activity using four PowerPoint slides and a handout (both below). I spend 5 to 10 minutes providing background information for the activity. I begin by describing the disproportionate impact of ozone pollution (smog) on certain communities by sharing information from a Scientific American article Pollution, Poverty and People of Color: Asthma and the Inner City (2012) and another article from The Revelator (2017), an initiative of the Center for Biological Diversity, titled Nothing to Wheeze At: Air Pollution's Disproportionate Effect on Poor and Minority Communities. I then share a Grist article Clean energy can bring climate justice to communities throughout America to explain how ozone pollution is produced and has its effects locally, such that solutions to the problem are local (I use the example of solar panels on roofs in a city). I contrast this with CO₂ pollution from fossil-fuel burning, which is a problem whose effects are global in scale. I describe the chemical reactions occurring in the atmosphere that produce the ozone molecules that are part of photochemical smog, which involve heat, sunlight, and NOx (NO, NO₂, other nitrogen oxides) and volatile organic compounds (VOCs). NOx and VOC chemicals are produced by combustion of gasoline and other fuels. I explain how smog is "bad ozone" in the lower atmosphere (troposphere) and that ozone in the upper atmosphere is considered "good ozone" because it protects living things on Earth from dangerous UV radiation. After this overview, students spend 15 to 30 minutes working on the activity, depending on how much time we have in the class session. By the time they encounter this activity, students have had a good deal of experience balancing chemical equations, using stoichiometric coefficients to calculate amounts of products and/or reactants, finding limiting reactants, calculating theoretical yield and reactant in excess, and applying these concepts to real-world issues (see Case Studies 13 and 14). They often need help getting started, particularly understanding which chemical equations and stoichiometric coefficients to use in a given calculation. For example, for Question (a), students need to use equations (2) through (4) on the first page, but some see nitrogen monoxide (NO) and think they need to use (1) and/or (5) in some way. The problem forces them to carefully think through which equations they need to use, based on the written descriptions of each chemical reaction given on the first page. Once they figure out which chemical equations to use, some also need help understanding that the molar ratios given by the stoichiometric coefficients are only valid with each balanced chemical equation, and not between two different ones. For example, for Question (a), some students try to create a single conversion factor by relating 2 moles of the NO reactant from equation (2) to 1 mole of the O₃ product in equation (4), but this is not valid and this approach to the problem will lead them to miscalculate in Question (b). Once they know the equations to use and how to apply the stoichiometric coefficients, most can do the rest of the activity without much trouble. If we run out of class time, I ask them to work on it on their own outside class for practice and then provide them with the solutions later.

Stoichiometry of Photochemical Smog.pptx (PowerPoint 2007 (.pptx) 2.3MB Sep10 24)

Stoichiometry of Photochemical Smog.docx (Microsoft Word 2007 (.docx) 22kB Sep10 24)

Case Study 15: Visualizing Charge-Based Interactions in Direct Air Capture (DAC) Aqueous Solutions (30 to 45 minutes). 

1. Identify full and partial charges on the solutes and the solvent in an aqueous solution.
2. Identify the solutes and the solvent in an aqueous solution.
3. Sketch the charge-based interactions among solutes and the solvent in an aqueous solution.

How I assess Case Study 15 Learning Goals: Case Study 15 Learning Goals Assessment.docx (Microsoft Word 2007 (.docx) 24kB Sep20 24) 

Course-level learning goal(s) targeted: 2

Case Study Description. I use this activity during a Zoom session that occurs late in the ninth week or early in the tenth week of the quarter. I try to do this as near to the beginning of aqueous solution chemistry as possible because students struggle to visualize molecules and ionic compounds in an aqueous solution. Doing this at the beginning of aqueous solution chemistry can help your students get off to a good start in terms of understanding what they are actually dealing with, at the molecular level, when they are working with aqueous solutions. If you lead this activity after the activity described for Case Study 11, you can use it with only the handout I provide below. If you choose to use this activity without using Case Study 11 first, you will need to spend some time explaining DAC to students using some of the teaching materials from Case Study 11. For this activity (Case Study 15), I ask students to identify full or partial charges on the different chemicals in a hydroxide-based DAC system (see Case Study 11). Students use Lewis structures and their knowledge about dissociation of ionic compounds into ions in aqueous solution to determine the charge of each solution component. Then, I ask them to sketch (draw) how the different chemicals in the DAC solution interact with each other based on their full or partial charges. Students sketch three different cases: one cation and anion alone in aqueous solution (Sketch 1), one molecule alone in aqueous solution (Sketch 2), and the case where the cation, anion, and molecule are all present together in aqueous solution (Sketch 3). This last case is still a simplification of the DAC system, but students' drawings can get complicated and "chaotic looking" quickly as they become full of molecules and ions!  By having students sketch the charged-based interactions, I can gain a "window" into what they visualize in their own minds when they think about an aqueous solution, which allows me to help them build a much better understanding of what a solution looks like at the molecular level.

Visualizing Solution Interactions Ionic and Molecular Components.docx (Microsoft Word 2007 (.docx) 322kB Sep9 24)

Case Study 16: Using the Dilution Equation to Estimate Benzene Contamination of Drinking Water From Fracking (5 to 15 minutes). 

1. Calculate solute concentration in an aqueous solution using the dilution equation (M₁V₂=M₂V₂).
2. Recognize that concentrations must have the same units if you want to compare them.

How I assess Case Study 16 Learning Goals: Case Study 16 Learning Goals Assessment.docx (Microsoft Word 2007 (.docx) 22kB Sep20 24)

Course-level learning goal(s) targeted: 5, 6

Case Study Description. I use this case study during a Zoom class session in which students practice using the dilution equation (M₁V₁=M₂V₂), which occurs late in the ninth week or early in the tenth week of the quarter. I use two PowerPoint slides (below) to structure this case study. The case study shows an additional application of the dilution equation (M₁V₁=M₂V₂), beyond the more typical application in a General Chemistry course that involves diluting a concentrated stock solution using a volumetric flask and pipette or graduate cylinder. The word problem provides unit conversion practice, specifically between molarity (mol/L) and mg/L and different volume units (gallons and liters). I start by reminding students about the "Fracking for Natural Gas in Pennsylvania" case study (see Case Studies 3 and 8) from earlier in the quarter and remind them that fracking has a serious potential to pollute drinking water and, in several case, it already has. (If you want to build this into a larger case study for your course, Fracking in America (2012) is a 23-minute-long documentary that tells the story of drinking water degradation due to fracking in rural communities of Pennsylvania, USA and what people living there are doing to address this problem.) I include a picture of the methane molecule (Slide 1) where I remind them about the fracking case study, to emphasize that so-called "natural" gas is fossil methane (CH₄), which is a greenhouse gas itself (and a stronger one than CO₂) that produces CO₂ when it is combusted. I also show screenshots from the Fracking in America documentary that show contaminated drinking water in people's homes. The word problem is on Slide 2. My focus is always on helping students understand how to set up the problem, apply the equation (dilution equation in this case), and answer the question being asked. With those things in mind, I use four polling questions (below) to scaffold this problem. For this problem, students need help figuring out which of the four terms in the dilution equation they will solve for (M₁,V₁, M₂ or V₂), as well as what to "plug into" the dilution equation for the other given terms. They also need help noticing that they will need to do a unit conversion (from molarity to mg/L, or vice versa) to compare the benzene concentration that they calculate (in mol/L, molarity) to the U.S. EPA's maximum contaminate level for benzene (in mg/L) in order to actually answer the question being asked. Many students stop short after finding the benzene concentration of the drinking water using the dilution equation and do not go on to actually answer the question, so I use polling questions 2, 3, and 4 to call their attention to the different units and the question that they are actually being asked to answer (i.e., "Should residents drinking the water be worried?"). Once they have figured out the plan for solving the problem, most students can do it fairly quickly.

Dilution Equation & Benzene Contamination.pptx (PowerPoint 2007 (.pptx) 506kB Sep10 24)

Dilution Equation & Benzene Polling Questions.docx (Microsoft Word 2007 (.docx) 14kB Sep10 24)

Case Study 17: Precipitation Reactions and Solubility Rules for Ionic Compounds: Direct Air Capture (5 to 10 minutes per problem). 

1. Apply the solubility rules for ionic compounds to predict precipitation in an aqueous solution.
2. Predict the ions dissolved in an aqueous solution when ionic compounds or acids are present.

How I assess Case Study 17 Learning Goals: Case Study 17 Learning Goals Assessment.docx (Microsoft Word 2007 (.docx) 23kB Sep20 24) 

Course-level learning goal(s) targeted: 1, 9

Case Study Description. When I am covering precipitation reactions and solubility rules for ionic compounds, I use the two real-world Direct Air Capture (DAC) word problems in this case study. I use these problems during the tenth week of the quarter during a Zoom class session. Before encountering these problems, students know soluble ionic compounds will dissociate into ions (becoming solutes) in aqueous solution. They are also aware of the solubility rules for ionic compounds and how to use them. I have also explained that ionic compounds deemed as "soluble" by the solubility rules are strong electrolytes and will undergo almost complete (100 %) dissociation in solution, whereas those compounds deemed "insoluble" are weak electrolytes and will undergo a tiny bit of dissociation. Prior to explaining this, most students think insoluble ionic compounds do not dissociate at all in aqueous solution. For example, in a typical solubility rules table found in General Chemistry textbooks, AgCl is deemed as "insoluble." As a result, students think there are no dissolved Ag⁺ or Cl^- ions present. While it is true that most AgCl remains in solid form and undissolved, AgCl has a K_sp value of 1.77 x 10^-10 and this means that there are small amounts of Ag⁺ or Cl^- ions present. By explaining electrolyte types and how they relate to the solubility of ionic compounds, students have a more nuanced understanding of the solubility rules that divide ionic compounds into the seemingly black-and-white categories of "soluble" and "insoluble."  This more nuanced understanding is important when applying chemistry to real-world problems. Finally, prior to or alongside of these problems, students spend time visualizing what dissolved ions look like in solution (see Case Study 15 and this 45-second video that I also use: Magnesium Sulfate (MgSO₄) Dissolving in Water Animated). The two problems that I provide in the PowerPoint (below) can be used to give students more practice with all of these concepts and/or serve as examples used to introduce these concepts. The two solubility problems in the PowerPoint can be used in any order, although the second one involves a little bit of acid-base chemistry knowledge (ionization of H₂CO₃ into H⁺ and CO₃^2- ions), so I use this one second since we cover acid-base reactions after precipitation reactions in my General Chemistry course.

The first DAC problem (Slides 1 and 2) deals with hydroxide-based DAC systems that use dissolved hydroxides to "capture" CO₂ molecules and precipitate them as carbonates (e.g., CaCO₃). If you didn't teach Case Study 11 and/or Case Study 15 prior to this problem, you will need to spend time providing students with enough background about hydroxide-based DAC reaction chemistry to understand the context for this problem. The bottom line with this problem is that the hydroxide has to be soluble in water to work for the DAC system. I give students four hydroxides to choose from (LiOH, NaOH, Mg(OH)₂, and KOH) and ask them to use solubility rules to decide which would be least effective for use in an aqueous hydroxide-based DAC system. I use a Zoom poll to collect their answers (see "DAC Hydroxide Solubility Polling Question.docx" below).

The second DAC problem is about what is done with the concentrated CO₂ captured by DAC to sequester it and keep it out of the atmosphere over long time scales. I use Slides 3 through 6 to structure this problem. This problem involves acid-base chemistry (H₂CO₃ ionizes into H⁺ and CO₃^2-), so I use this problem as we move into acid-base chemistry (which I cover right after precipitation chemistry. I present a technology that uses basalt-rich rocks, as described in a Volts podcast The cheapest way to permanently sequester carbon involves ... fizzy water and a scientific paper (2014) CO₂ storage potential of basaltic rocks in Iceland and the oceanic ridges. The technology is being developed by an Icelandic company called Carbfix because there is a lot of underground basalt in that region. (I also mention a local example of basalt rocks near the Columbia River in Washington State, USA, as a reference point for what basalt looks like, but note that these rocks are above ground and would not be used for this technology.) The idea is that the compressed CO₂ "captured" by DAC is injected into groundwater that is in contact with basalt rock and Mg- and Ca-containing carbonates are produced. When the CO₂ is added to the groundwater, it creates "fizzy" water similar to a carbonated beverage (I use a picture of carbonated water on Slide 3). I ask students to use a (very generalized) chemical formula for basalt (CaMgSiO₄), their knowledge about DAC chemical reactions (when CO₂ enters water it reacts with H₂O molecules to form H₂CO₃, then H₂CO₃ ionizes to give CO₃^2-), and solubility rules for ionic compounds to tell me which solids will form when CO₂-rich water comes into contact with basalt rock. I scaffold this real-world problem for them using three Zoom Poll questions (see "DAC CO₂ Sequestration Polling Questions.docx" below), which allow them to determine which ions are present in this system (Questions 1 and 2) and what will happen when they come into contact with one another (Question 3). I wrap up the case study by pointing out that the CO₂ that was previously in the atmosphere is now sequestered underground in solid form and is predicted to stay there for thousands of years. (I include Slide 6, which I presented to them earlier in the quarter, to address questions from students who think Si⁴⁺ and O^2- ions are present. Although their periodic table group number predicts these ions, I remind them that these ions tend to be present in environments on or near the surface of the Earth as part of polyatomic ions, not on their own as monoatomic ions.)

Precipitation Reactions in DAC.pptx (PowerPoint 2007 (.pptx) 1.4MB Sep11 24)

DAC Hydroxide Solubility Polling Question.docx (Microsoft Word 2007 (.docx) 13kB Sep10 24)

DAC CO2 Sequestration Polling Questions.docx (Microsoft Word 2007 (.docx) 14kB Sep10 24)

Case Study 18: Redox Chemistry, Green Hydrogen, and Displacement of Indigenous People (20 minutes). 

1. Describe the direction of electron transfer among reactants in an oxidation-reduction reaction.
2. Identify the oxidized and reduced reactants in an oxidation-reduction reaction.

How I assess Case Study 18 Learning Goals: Case Study 18 Learning Goals Assessment.docx (Microsoft Word 2007 (.docx) 24kB Sep20 24)

Course-level learning goal(s) targeted: 5, 6, 7, 8, 9, 10

Case Study Description. I use this case study during a Zoom class session near the end of the tenth week or beginning of the eleventh week of the quarter when students learn oxidation-reduction (redox) chemistry. The three redox reaction practice problems in this case study can be used to help students understand and practice redox concepts, terminology, and key skills (e.g., electron transfer from one reactant to another; assigning oxidation numbers (ONs); using ONs to identify reduction and oxidation and agents). I start with the story of how the Howeitat tribe is being displaced by the Saudi Arabian government, through eminent domain, to make way for a futuristic city (named NEOM) to be powered by renewable energy (e.g. wind, solar) and serve as a hub for "green" hydrogen fuel (H₂) production. I explain this on Slide 1 using information from four news articles: Saudi Arabia's Neom Project, the Howeitat Conflict and Tribe-State Relations by E-InternationalRelations.net, which explains the complexity of the situation and division regarding the situation within the Howeitat Tribe; Neom: Saudi Arabia jails nearly 50 tribespeople for resisting displacement by MiddleEastEye.net and Saudi Arabia: UN experts alarmed by imminent executions linked to NEOM project by the United Nations Human Rights Office of the High Commissioner, which report how Howeitat individuals who resist displacement from their land are being imprisoned and executed; and Saudi Arabia has a new green agenda. Cutting oil production isn't part of it by Grist, which describes the overall strategy of the Saudi Arabian government for becoming carbon-neutral (including where NEOM fits into the picture). I then explain what "green" hydrogen is and use the redox reaction by which H₂ gas (fuel) is produced as an example problem (Slide 2). Before I show them how to assign ONs and determine which reactant is oxidized and which is reduced, I use a Zoom poll to ask them which molecule donates electrons during the redox reaction (on Slide 2) and which molecule accepts those electrons. For all the redox reactions I present to students, I strive to ask them which reactant donates the electron and which accepts the electron to emphasize that electrons are transferred among reactants in redox reactions. It is important that students keep this "big picture" in mind because they often lose sight of this when they get lost in the details of assigning ONs to each element in each reactant and product, and using the ON change to identify which reactant is reduced and which is oxidized. As they get lost in the mechanics of all of that, they forget there is an electron transfer happening. At first, when students look at this electrolysis reaction (on Slide 2), they see that there is only one reactant and this can cause confusion. What they need to notice is that the stoichiometric coefficient for the reactant is 2, which means that one of the water molecules donates the electrons and the other accepts it. Thus, this example provides a case where the reactants are the same type of compound and how to work through this type of problem. After the Zoom poll, I show them how to assign ONs to confirm that this is a redox reaction. This is a very simple example and does not take much class time to explain.

After the first redox reaction example, I tell students that hydrogen fuel is an energy-dense fuel that can replace the fossil fuel-derived fuels currently used to power large and heavy modes of transportation (e.g., airplanes, ferries). I show them the combustion reaction for H₂ fuel and assign ONs. I don't spend much time explaining this redox reaction because it is the reverse of the electrolysis of water reaction I just explained and the ONs are the same. I show students the first one minute and twenty seconds of the video How does a hydrogen fuel cell work?, which is a silent video but shows how the cell works at the molecular and ion level and how electricity is harnessed from the combustion of H₂ fuel. If you are teaching electrochemistry, specifically anodes and cathodes, the video highlights this. (The General Chemistry curriculum at my college does not cover electrochemistry until the third quarter of the three-quarter-long series, so I do not emphasize this aspect of the video during this first-quarter General Chemistry course.) If you run out of time to show the video, and I sometimes do, you can tell students that they can watch it on their own to learn more about how the redox reaction for the combustion of H₂ works inside a hydrogen fuel cell. After showing the video, I tell students that H₂ fuel is considered "clean burning" because the combustion reaction for H₂ gas does directly not emit CO₂ into the atmosphere, but that CO₂ may have been emitted to produce the H₂ fuel in the first place when the electrolysis of water is not powered by renewable energy (e.g., wind, solar). This information provides a transition to the third and final redox example of this case study, which is focused on a redox reaction that uses methane gas (CH₄) derived from fracking as a reactant. When H₂ fuel is produced in this way, it is known as "grey" hydrogen (Slide 5). For this example, I use a Zoom poll to collect feedback in which I ask students to identify which molecule is reduced and which is oxidized, as well as how electrons are transferred during the reaction. I include all reactants and products as multiple choice options in this poll, as many students struggle with using redox concepts and terminology in a precise manner, thinking that reaction products are oxidized or reduced and/or that electrons are transferred from reactants to products, when it is really the reactants that are the focus (I emphasize that the transfer creates the products, but there is not a transfer between reactants and products). The chemical reaction used to produce "grey" hydrogen also provides a redox example where the C in the CO product and the C in the CO₂ product have different oxidation numbers. This example shows students how to deal with redox reactions when that is the case. I end this case study with two slides showing that "blue" hydrogen uses the same chemical reaction to produce H₂ fuel from CH₄, but that it captures the CO₂ released (a product of the redox reaction) using CCS technology. (CCS is Carbon Capture and Storage, and I provide a link to the U.S. Congress Research Service Report Carbon Capture Versus Direct Air Capture (2020) if students want more information. I also make sure to know the general difference between DAC and CCS, and provide a short description on Slide 6, just in case a student asks.) Finally, I show students how much more CO₂ is emitted to the atmosphere, per Kg of H₂ fuel produced, when fossil fuel energy sources (e.g., coal, oil, "natural" methane gas) are used to power H₂ fuel production (Slide 7).

Green Hydrogen Fuel Native Lands.pptx (PowerPoint 2007 (.pptx) 1.5MB Sep17 24)

Green Hydrogen Polling Questions.docx (Microsoft Word 2007 (.docx) 15kB Sep11 24)

Grey Hydrogen Polling Questions.docx (Microsoft Word 2007 (.docx) 16kB Sep11 24)

Case Study 19: Redox Chemistry and Lung Damage from Air Pollution (5 to 10 minutes). 

1. Describe the direction of electron transfer among reactants in an oxidation-reduction reaction.
2. Identify the oxidized and reduced reactants in an oxidation-reduction reaction.

How I assess Case Study 19 Learning Goals: Case Study 19 Learning Goals Assessment.docx (Microsoft Word 2007 (.docx) 22kB Sep20 24) 

Course-level learning goal(s) targeted: 5, 6

Case Study Description. I use this case study during a Zoom class session near the end of the tenth week or beginning of the eleventh week of the quarter when students learn oxidation-reduction (redox) chemistry. The redox reaction problem that is part of this case study can be used to help students understand and practice redox concepts, terminology, and key skills (e.g., electron transfer from one reactant to another; assigning oxidation numbers (ONs); using ONs to identify reduction and oxidation and agents). Students already know the climate justice issue of marginalized groups being disproportionately affected by PM 2.5 pollution, which I touch on in Case Studies 1, 4, 9, and 13. When I present these case studies in class, many students want to know how, exactly, the PM 2.5 particles harm our bodies. With redox chemistry, I can finally give them a partial answer. I use two PowerPoint slides to structure this case study. The first slide is a graphic from the 2016 Nature journal article Chemical exposure-response relationship between air pollutants and reactive oxygen species in the human respiratory tract, which I use to show students how chemicals in PM 2.5 pollutants cause oxidative stress to the epithelial lining in our lungs. On the second slide, I provide an example of one of the many redox reactions that cause oxidative stress in human lungs. I use a Zoom poll to ask students to identify which molecule is reduced and which is oxidized, as well as how electrons are transferred during the reaction. I include all reactants and products as multiple choice options in this poll, as many students struggle with using redox concepts and terminology in a precise manner, thinking that reaction products are oxidized or reduced and/or that electrons are transferred from reactants to products, when it is really the reactants that are the focus (I emphasize that the transfer creates the products, but there is not a transfer between reactants and products).

Lung Damage Air Pollution.pptx (PowerPoint 2007 (.pptx) 222kB Sep12 24)

Lungs Air Pollution Oxidative Stress Polling Questions.docx (Microsoft Word 2007 (.docx) 16kB Sep12 24)

Case Study 20: Nuclear Energy: Should It Stay or Should It Go? (20 to 30 minutes). 

1. Reflect on the ethics and safety of nuclear energy as a way to address the climate crisis.
2. Identify the chemical and physical forms of a compound or element in a real-world system.

How I assess Case Study 20 Learning Goals: Case Study 20 Learning Goals Assessment.docx (Microsoft Word 2007 (.docx) 22kB Sep20 24) 

Course-level learning goal(s) targeted: 1, 5, 6, 7, 9, 10

Case Study Description. I use this case study during the eleventh week of the quarter when students learn about radioactivity and nuclear chemistry, which is the last topic I cover in my course. The case study has a systems-thinking focus of identifying the possible chemical forms (atom, ion, molecule, ionic compound - see Case Studies 1, 3, 7, 8, and 11) of a radioactive nuclide in a real-world system. I use a PowerPoint presentation to structure this case study. I use Slides 1 through 3 as a thought-provoking way to begin the radioactivity and nuclear chemistry section of the course. I present an image (Slide 1) of two protests from a 2022 Grist article called Save the nukes?: one from the 1980s and one from 2022, both focused on the Diablo Canyon Nuclear Power Plant in San Luis Obispo, California. I explain that, in the 1980s, there was opposition to the Diablo Power Plant being built, but today (2022) people are fighting to keep it open because using nuclear power generation does not directly emit CO₂ or other greenhouse gases to the atmosphere (but there is mining, processing, transportation associated with nuclear plant construction that does cause indirect or "life cycle" emissions). The question at the heart of all this is "Is nuclear energy 'clean' energy when it comes to the climate crisis?" I use the first Zoom polling question (see "Nuclear Energy & Climate Polling Questions.docx" below) to ask students what they think. Since we just finished redox and a case study about H₂ fuel (see Case Study 19), I use Slide 2 to quickly note that H₂ fuel production powered by nuclear energy results in much lower CO₂ emissions than fossil fuels (e.g., coal, oil, natural gas). I use Slide 3 to present a quick climate-justice case study about nuclear power generation in Hanford, Washington, USA and how that has affected salmon and other aspects of the Columbia River along with the Yakama Nation and other Indigenous peoples' land in the area. If you have time to make this into a longer case study by sharing more of the human story with students, you could show students a 24-minute-long documentary called Salmon People: A Native Fishing Family's Fight to Preserve a Way of Life, which shows why salmon are important to these tribes and how they are affected by the loss of salmon. Although the video does mention climate change, there is not a specific mention of water pollution by radioactive isotopes. However, the video does an excellent job of conveying the importance of salmon to tribes through a family's story of loss. You could ask students after the video "What do you already know about radioactive chemicals and salmon in the Columbia River?" and "What would you like to know about radioactive chemicals and salmon in the Columbia?" as a way to transition to the chemistry involved.

After students learn about the different types of nuclear decay (alpha, beta, positron emission, and electron capture), and how to predict the parent or daughter nuclide and type of decay, I use Slides 4 through 8 for a systems-thinking question. On Slide 4, I show students a picture and example of a mineral (and its general chemical formula) from which radioactive nuclides (e.g., Uranium-235) come, tell them that these minerals are acquired through mining and processing of uranium-rich rocks, and remind them about pollution of the Columbia River due to the Hanford Nuclear facility in Washington, USA. I ask them to think about all of these environmental systems, and then tell me what chemical forms are possible for U-235 in these environments by answering a Zoom poll (see Question 2 of "Nuclear Energy & Climate Polling Questions.docx" below). Afterward, I debrief using their poll responses by discussing how minerals in rocks are ionic compounds that can dissolve into water to become ions (e.g. groundwater, Columbia River water, etc). (U-235 can also be present in a molecule, UO₂, but I do not mention this unless students ask because the general rule we've used all quarter, for this first-quarter of General Chemistry, is that compounds with metals and nonmetals tend to be ionic compounds. If students do ask, I explain that there are always exceptions to these general rules in chemistry and that the rules used in first-quarter General Chemistry are simplifications and that they will learn more in a later General Chemistry course.) On Slides 6 through 8, I emphasize that it is usually only noble gases (Group 8A) that will be naturally present in real-world environments (at the temperature and pressure at the Earth's surface) as non-bonded neutral atoms. I do this here because a large number of students think U-235 exists as a neutral atom, based on Zoom poll results. Based on my observations, this is because students focus on the nucleus during the radioactivity section of a chemistry course, and forget or fail to recognize that the nucleus is still surrounded by electrons and that nuclides (U-235) can exist as charged ions dissolved in water (groundwater) or bond to form a molecule and/or ionic compound (in minerals and rocks). Students struggle to conceptualize isotopes as anything other than non-bonded neutral atoms, unless explicitly told otherwise. This makes sense because radioactive isotopes are not presented as ions or as a part of molecules or compounds in most General Chemistry textbooks. The focus is instead on the nucleus. It is rare to see nuclides portrayed (in textbook pictures, graphics, etc) with both nucleus and surrounding electrons together, let alone as an ion in aqueous solution or part of an ionic compound or molecule. I explain this on Slide 7 and remind them that the U-235 nucleus is surrounded by electrons and that U-235 atoms do not have an octet (i.e., not likely to exist as a neutral atom). On Slide 8, I walk students through the flow diagram I created, which they have seen multiple times this quarter (see Case Studies 1, 3, 7, 8, and 11) and have used as a general guide to determining chemical form (but there are always exceptions and this flow diagram is a simplification).

After students learn about fission and nuclear power generation, I use Slides 9 through 14 to wrap up the case study. I refer them to a recent (2024) Volts podcast Nuclear? Perhaps! to learn more (Slide 9) and summarize some of the pros and cons of nuclear energy (Slides 10 through 14). Finally, on Slide 15, I ask them for their opinion on whether nuclear power generation is a good way to address the climate crisis, now that they know more about it (see Question 3 of "Nuclear Energy & Climate Polling Questions.docx" below).

Nuclear Energy Should Stay or Go.pptx (PowerPoint 2007 (.pptx) 5.7MB Sep13 24)

Nuclear Energy & Climate Polling Questions.docx (Microsoft Word 2007 (.docx) 14kB Sep17 24)

Case Study 21: Water Contamination, Food Production, and Human Health in the San Joaquin Valley, California, USA (30 to 60 minutes). 

1. Identify the chemical and physical forms of a compound or element in a real-world system.
2. Explain how an element or compound dissolves in water using charge-based interactions.
3. Explain how to determine the chemical forms of a compound or element using the periodic table and/or the octet rule.
4. Explain how to determine the physical form of a compound or element using their melting and boiling points and temperature data about the environment in which they exist.

How I assess Case Study 21 Learning Goals: Case Study 21 Learning Goals Assessment.docx (Microsoft Word 2007 (.docx) 22kB Sep20 24) 

Course-level learning goal(s) targeted: 1, 2, 3, 4, 5, 6, 9

Case Study Description. This case study has a systems-thinking focus, with specific focus on students' ability to identify the possible chemical forms (neutral atom, charged ion, ionic compound, molecule) and physical forms (solid, liquid, gas, dissolved) of an element or compound in a real-world system. In this case study, students are also asked to use melting and boiling points, their knowledge of aqueous chemistry, and/or the octet rule to explain how they identified the forms. I work with students on developing these chemical systems-thinking skills throughout the quarter (see Case Studies 1, 3, 7, 8, 11, and 20) and this case study is a culmination and synthesis of what they have learned. It is focused on groundwater contamination in the San Joaquin Valley (SJV) of California, USA, which is a major supplier of vegetables, fruits, and nuts to U.S. citizens. It has over 100,000 oil and gas wells, which pollute the groundwater, potentially compromising the safety of the food grown there (the groundwater is used for agriculture) and contaminating the drinking water of the mostly Latino agricultural workers who live there and rely on rural wells. Other activities pollute SJV water, including fertilizer and animal manure, but this activity focuses on only the contaminants from oil and gas development. The activity is centered on a research study Vulnerability of Groundwater Resources Underlying Unlined Produced Water Ponds in the Tulare Basin of the San Joaquin Valley, California published in 2021, which presents chemicals detected in "unlined PWPs" that store wastewater from oil and gas development. (A PWP is a "produced water pond." These ponds are called "unlined" because there is no barrier preventing the waste from seeping into groundwater.) On the handout (below), I present students with Figure 3 from the research study and information about air and groundwater temperatures in the SJV. They use this information to identify all possible chemical and physical forms of some of the chemicals shown in Figure 3. They also provide explanations of how they know, for a few of the questions. I offer this activity for extra credit points at the end of the quarter, which are credited to student lab scores, as I often run out of class or laboratory time for it. However, by the end of the quarter, students are happy to earn extra credit toward their laboratory score and 80 to 90 % of students in the class choose to complete it. I also remind them that this is a good review for the final exam!

Water Agriculture Fossil Fuel San Joaquin Activity.docx (Microsoft Word 2007 (.docx) 343kB Sep13 24)

I share a lot of case studies here. During every quarter that I teach this course, I cannot always implement every one of them to the full extent described here. During some quarters, the timing of national holidays, the occurrence of snow days, and the schedule of my college's professional development days do not always allow me to implement every single one. In addition, some groups of students ask a lot more questions during class time than other groups do; in those cases, my time for these case studies is shortened. In all of these instances, I provide case studies to students as extra optional practice along with a video that presents the issue and explains the solutions to any word problems, provides them as extra-credit opportunities, and/or omit some of the engaging videos that are less essential for students' learning chemistry content and instead briefly describe what is shown in the video and provide them with the link in case they want to watch it. However, I have found that showing the accompanying video(s) is important for student engagement.

If you are worried about the case studies taking too much time in your course, you can "tightly script" what you say when you are giving a presentation. I do this all the time; it allows me to stay focused on the essential information that I need to deliver and then direct students to additional resources (e.g., web links to articles, documentaries, YouTube videos, books, etc.) where they can spend more time on their own learning more if they desire. The case studies are well worth presenting, because I have observed how engaging they are to students. I began teaching in this way and threading climate justice through my General Chemistry course during the pandemic, when we all taught remotely and stared at faceless Zoom screens while we lectured. During this time, I noticed that students would "perk up" and start asking questions in the Zoom chat whenever I would present a compelling and engaging climate-justice case study and tell a human story. This is in contrast to the rest of the Zoom class session when I covered the abstract and seemingly (to them) disconnected chemistry content, which is when the Zoom chat was silent and inactive. I typically don't have time in my chemistry class to explore the information sources on my slides with students in great detail, aside from giving them a few-minute overview, but I do always provide links to information sources on the PowerPoint slides and tell students that they have the links and can explore more on their own if they wish. I share all of my slides on our LMS (Canvas) ahead of each class session, so that students can download them, follow along as we move through each class session, and save them for later reference.

Asking students to solve real-world problems helps them build the knowledge, skills, and dispositions needed to apply chemistry in their future careers and in their lives. However, moving from textbook to real-world problem-solving with chemistry can be challenging for students who don't have a full understanding of the meaning and application of chemistry vocabulary. Using lots of real-world examples helps students gain practice with this, so that they can build their critical thinking skills and become more comfortable when word problems are not worded and set up exactly as they are in the textbook. For students who have taken previous chemistry classes and are accustomed to learning chemistry "by the book" only, it can take a little while for them to get comfortable solving real-world problems. However, once they start gaining confidence and building the critical thinking skills needed to do this, their problem-solving skills improve drastically. This can help them in future chemistry courses, in other STEM courses that have a problem-solving focus (e.g., physics), and prepare them for their future STEM majors and careers.

When using case studies, telling the stories of people and communities is of the utmost importance when it comes to engaging students. Starting with a story first before delving into the chemistry, helps to humanize and contextualize abstract STEM content and connect it to the real world and students' lives. Mountaineer, photographer, and writer Cory Richards articulates the central role of stories in the human experience on pages 347 and 348 of his recent book The Color of Everything (2024): "Storytelling is what we use to navigate life as well as transcend death. Story is consciousness. It drives discovery and belief and even psychology and science as we try to figure out and explain the why of things. Story is also the architecture of identity. We become 'I' and the stories we tell ourselves not only guide us but become us. We say 'I am this' and 'You are that' and become certain of far too much. Story is the bedrock of everything we do and all the relationships we have. With others. With the world around us. With ourselves. Make no mistake, storytelling is the most important thing we do. To tell stories is to be human." Our students can engage with chemistry more deeply and with more interest and excitement when it is presented in the context of human stories. I subscribe to the nonprofit newsroom Grist's email feed, which helps me keep up-to-date on climate and environmental justice-focused news stories that are often told from the perspective of the affected people and front-line communities in the form of stories. Grist also tends to focus on "solutions journalism," where I can find positive stories of change to share with students.

I strive to bring positive stories of change into my course whenever possible, so that students hear about how people are addressing climate injustices and climate change and see that changes are changing for the better. This is a necessary component of climate education and is needed for climate adaptation. If you would like to learn more about this, please watch this 28-minute presentation, Hope is Not Optional, in which I summarize work related to hope, empowerment, and the importance of a solutions focus articulated by Elin Kelsey, Jennifer Atkinson, and others. Because this is so important, I always recommend actively seeking out and sharing positive stories of change with your students, such that if you opt to use only a subset of the case studies that I shared here, and none of them include positive stories of change, you find your own stories to share related to the case studies that you do opt to use. (I share resources in the Reference and Resources section below where you can find news stories, magazine articles, and other information that highlight the good news and positive stories of change related to the issue of climate.) I especially try to highlight stories that go beyond technology-based solutions and toward civic engagement. I do use technology-based examples throughout the course, as well as stories focused on civic engagement. Whenever possible, I highlight civic engagement examples that show ways that marginalized communities can advocate for themselves and create positive social change. A focus on showing examples of empowerment by marginalized communities is especially important when bringing climate-justice case studies into your course. Impacted communities are often labeled as oppressed and passive by people outside the community, while in reality they are engaged and empowered in addressing the challenges they face. This deserves attention because positive stories of action and change in these communities are typically not included in the mainstream media, where the affected individuals/communities are often portrayed as passive participants, as opposed to governments, business interests, and other stakeholders who are portrayed as more active.

When I first started the systems-thinking work, I was surprised that, when given a specific element or compound, many students could not correctly identify the element or compound as possibly existing as an atom, ion, molecule, and/or ionic compound in a given real-world system. Many students struggle with this throughout the quarter. This was eye-opening for me. As chemistry instructors and practitioners, we take for granted that students can do this. As instructors, we give them the basic definitions of atom, ion, molecule, and ionic compound near the beginning of a chemistry course or series, assume they have a good understanding of each after we present the definitions, and then don't really come back to them explicitly. However, in my experience, students do not have this understanding and they need a lot of repetitive practice and support. As a result, I have chosen to include systems-thinking polling questions and activities whenever I can throughout my class and laboratory sessions. One major systems-thinking concept students struggle with is that chemicals in the real world (at the temperatures and pressures of the Earth's surface or near-surface) are not present as non-bonded neutral atoms, and are instead much more often part of molecules or ionic compounds or dissolved as ions in aqueous solutions. This is something I strive to emphasize and remind students of throughout the quarter. Students are not accustomed to thinking about complex, multi-component real-world systems in 100- and 200-level chemistry courses. Before asking students questions about real-world systems, it helps to remind or prompt them to think about all parts of the system and the types of matter that are present. For example, when I ask students to think about the physical (solid, liquid, gas, dissolved) and chemical (atom, ion, molecule, ionic compound) forms in a real-world fracking system, I remind them about all the parts of the system (e.g., there is solid rock underground, there are gases in the atmosphere, there is water underground in the aquifer and in the drinking water wells of homes and solutions exist when there is water).

The social justice issues presented in these case studies are "anchoring phenomena," which are occurrences "in the natural and human-made world that can be observed and cause one to wonder and ask questions" (Phenomena and the NGSS). Phenomena-based instruction is a primary feature of the K-12 Next Generation Science Standards. And in addition to broadening participation of groups that have been marginalized in STEM (see Equity Ethic described at the beginning of the Description and Teaching Materials section above), centering STEM teaching on social justice issues is just good teaching practice. A "phenomenon" causes students to "wonder and ask questions," and it can also serve as an "anchoring point," which is something you can keep coming back to throughout the quarter when the chemistry content and skills you are teaching connect to the social (climate) justice issue. In other words, you can come back to a case study you used at the beginning of a term when you are covering new chemistry content that is also relevant to the case study later on in the term. This is helpful in many instances, such as when you feel like you are losing students' focus and attention. You can often get it back by referencing a compelling social (climate) justice issue you already covered. Also, a case study that you introduced early in the quarter becomes what is known as "prior knowledge" (e.g., Activating Prior Knowledge). This is important because when students are learning new and abstract chemistry content, they learn best and retain information better when they can connect it to something they already know. The climate-justice case study is a human story and, once introduced to them, it becomes their "prior knowledge." For more information, watch Social Justice Issues As Phenomena, in which panelists Dr. Salina Gray and Dr. Alexis Patterson Williams describe how this works. The San Diego County Office of Education also has a good web page that describes Phenomena and the NGSS.

I have taught this course synchronously on Zoom since the Fall of 2020 during the pandemic and have thought and experimented a lot with teaching practices that I think are effective in this context. My first lesson was that Zoom breakout rooms do not work for group work, as most faculty members figured out very early on. Most of my community college students, a good number of which are sixteen- to eighteen-year-old "Running Start" students who are juniors or seniors in high school, are not generally proactive and/or skilled enough in managing group dynamics to start talking with each other to organize group work over Zoom. In fact, a few of my students would be driving in their vehicle listening to Zoom, on their way to an appointment or another class, when I thought they were actively working together with their group in a breakout room on a problem while sitting at a desk or other stationary space conducive to active learning! As a result, I quickly pivoted to pausing the lecture for an appropriate amount of time so that students could work individually on problems during the Zoom class time, which is valuable because they have a chance to ask me questions and watch me work through sections of the problem when they or another student asks for help. During these pauses in lecture time while students are working, I encourage them to ask as many questions as they would like or ask me to go over parts of the problems they are attempting but completely stuck on, to ensure that I am engaging with them the whole time. This works well because then all students in the class can hear the questions asked and my feedback and watch me work through problems. Also, some students direct-message me in the Zoom Chat, such that other students cannot see their question. This encourages more reserved or anxious students to participate and ask questions. In this case, I will often copy-and-paste the question to the general chat so that all students can see it and read it aloud, before I answer it. Some students skip the Zoom class sessions altogether (the weekly 2-hour and 50-minute-long laboratory sessions are required attendance), for what I would consider both valid and invalid reasons. As a result, I record each session and they can watch later. I teach early morning chemistry classes and have had many students come straight to class from working full-time for the night shift at a local hospital. Recording gives these students a chance to get some sleep and watch the recording later. Other students may have stayed up late doing homework after working a full-time job all day and then caring for children, and opt to get some sleep to refresh their mind instead of coming to the "live" class session. In all of these cases, I emphasize that they need to be proactive in getting their questions answered when they miss class, either from me, or another student, or a campus tutor. At the beginning of the quarter, I have a one-on-one 10- to 15-minute meeting with each student to learn their plan for class attendance and for keeping up with the coursework. International students who are English Language Learners have told me that they appreciate the recordings because they can go back and watch sections that they missed. For longer activities (e.g., Case Studies 2, 6, 11, 14, and 15) that students start in class but do not always finish during class time, I provide a video of me describing step-by-step the solution to all problems related to the activity. I believe that the flexibility of a hybrid General Chemistry course, with in-person laboratory sessions, serves community college students well, as they are often juggling full-time jobs, family responsibilities, and other major obligations.

Case-Study Specific Learning Goals

Please see the "Description and Teaching Materials" section for information about assessment of case study-specific learning goals, which are those that I assess as part of a specific case study. Within separate and downloaded Word files provided at the end of each case study description and the links to the teaching materials for it, I explain how I determine whether students are achieving the learning goals specific to each case study.

Course-Level Systems Thinking and Climate Justice Learning Goals

These learning goals are not assessed as part of each case study that targets them, but instead define the overarching systems thinking and climate justice learning goals for my entire course. I do not assess them as part of every case study due to time limitations, but also because no single case study is designed to support all of them. When I assess these learning goals, I use a pre-post quarter survey¹ and pre-post quarter case study analyses¹, which students complete at the start and end of the course. I strive to support these learning goals with my teaching materials in a cumulative way, as a result of students' exposure to many systems thinking and climate justice case studies over the 11-week-long General Chemistry course. For those interested in assessing one or more course-level learning goals (listed below) as part of specific case studies, I provide information about how I assess each course-level learning goal (Word file below) using specific questions from the pre-post quarter surveys and pre-post quarter case-study analyses (also provided as Word files below). In the "Description and Teaching Materials" section, I also note which of these course-level learning goals is targeted by each case study (even though I do not assess it as part of that case study) and I include them explicitly as case study-specific learning goals if I do assess them as part of the specific case study.

1. Identify the chemical and physical forms of a compound or element in a real-world system.
2. Explain how an element or compound dissolves in water using charge-based interactions.
3. Explain how to determine the chemical forms of a compound or element using the periodic table and/or the octet rule.
4. Explain how to determine the physical form of a compound or element using their melting and boiling points and temperature data about the environment in which they exist.
5. Identify social, political, moral, environmental, health, and economic challenges in a real-world case study.
6. Identify who is most impacted by a climate justice issue and explain how they are impacted.
7. Propose ways that those most impacted could address the climate injustice they face.
8. Build a critical consciousness toward understanding the systemic nature of climate injustice.
9. Recognize that STEM can be used as a tool to address climate injustice.
10. Recognize that climate change will disproportionately impact marginalized groups.

How I assess Course-Level Learning Goals: Course-Level Learning Goals Assessment.docx (Microsoft Word 2007 (.docx) 28kB Sep20 24)

NOTE: I refer to this pre-post survey (Pre-Post Quarter Survey Questions.docx (Microsoft Word 2007 (.docx) 16kB Sep19 24)), these pre-post case-study analyses (Pre-Quarter Fracking Case Study.docx (Microsoft Word 2007 (.docx) 26kB Sep19 24) and Post-Quarter Coal Ash Case Study.docx (Microsoft Word 2007 (.docx) 1.8MB Sep19 24)), and this case study assessment rubric (Case Study Assessment Rubric.docx (Microsoft Word 2007 (.docx) 24kB Sep20 24)) in the "Course-Level Learning Goals Assessment.docx" Word file.

This work is supported in part by NSF-IUSE grant (DUE 2043535).

¹The pre-post quarter surveys and case-study analyses were developed for a research study funded by a National Science Foundation grant (DUE 2043535), in collaboration with Dr. Heather Price at North Seattle College, Seattle, Washington, USA and Dr. Irene Shaver, Climate Solutions Program Manager for the Washington State Board of Community and Technical Colleges.

Nivaldo Tro, 2018, Chemistry: Structure and Properties (2nd Edition)

Nearpod(free online classroom polling application)

Ebony McGee and Lydia Bentley (2017) The Equity Ethic: Black and Latinx College Students Reengineering Their STEM Careers toward Justice (research article)

Vicente Talanquer, 2019, Some insights into assessing chemical systems thinking, Chemistry Education Research, American Chemical Society (research article)

Sonya Doucette, 2022, Systems Thinking and Civic Engagement for Climate Justice in General Chemistry: CO₂ and PM 2.5 Pollution from Coal Combustion, Curriculum for the Bioregion Activity Collection, Science Education Resource Center, Carleton College (online curriculum)

Hannah Ritchie, 2019, Who has contributed most to global CO₂ emissions?, Our World in Data (article)

PubChem, online database of chemical information, National Library of Medicine, National Institute of Health (database)

United States Environmental Protection Agency, 2021, Climate Change and Social Vulnerability in the United States: A Focus on Six Impacts (report)

Grist, 2022, How a breakthrough in geothermal could change our energy grid (video)

Climate Justice Alliance (organization)

SciToons, 2018, Color by Size: Quantum Dots (video)

TEDx talk, 2014, Turning CO₂ into oil: Lisa Dyson at TEDxFulbright (video)

Public Broadcasting Service (PBS), 2016, Quantum Physics to Protect Votes (video)

Renee Cho, 2023, The Energy Transition Will Need More Rare Earth Elements – Can We Secure Them Sustainably?, Columbia Climate School (article)

Associated Press, 2022, Myanmar bears the cost of green energy (video)

The Guardian, 2022, Lithium mine pits electric cars against sacred Indigenous land (video)

DW Planet A, 2021, Can you recycle an old EV battery? (video)

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Laurence Knight, 2014, Who's afraid of bromine?, BBC News (article)

Lylla Younes, Ava Kofman, Al Shaw, and Lisa Song, 2021, Poisons in the Air, ProPublica article)

ProPublica (organization)

Al Shaw and Lylla Younes, 2021, updated 2023, The most detailed map of cancer-causing industrial air pollution in the U.S., ProPublica (interactive map)

U.S. EPA's Toxic Release Inventory (database)

Naveena Sadasivam and Lylla Younes, 2023, EPA announces rules curbing cancer-causing pollution from chemical plants Grist (article)

Mandana Ehsanipour, 2024, Research Project on Pollutants in Sacrifice Zones for Chemistry Courses: The Role of Industry, Governments, Local Communities, and Scientists, Curriculum for the Bioregion Activity Collection, Science Education Resource Center, Carleton College(online curriculum)

Jana Cholakovska and Nate Rosenfield, 2023, Workers Are Dying From Extreme Heat, Grist (article)

Siri Chilukuri, 2023, Why Extreme Heat Is So Deadly For Workers, Grist (article)

Frida Garza, 2023, Heat Waves Are Making Restaurant Kitchens Unsafe, Grist (article)

The Lawrence Hall of Science, Vibration of Molecules CHEM Study, CHEM Study project (video)

Minute Earth, 2015, How Do Greenhouse Gases Actually Work? (video)

Frida Garza and Ayurelle Horn-Muller, 2024, Biden Admin Unveils First-Ever Heat Protections For Workers, Grist (article)

Intergovernmental Panel on Climate Change, United Nations (intergovernment panel)

Jesse Nichols, 2023, Should we pull carbon out of the air with trees, or machines?, Grist (video)

Negative Emissions Technologies and Reliable Sequestration: A Research Agenda, 2019, National Academy of Sciences Report

Baciocchi et al, 2006, Process design and energy requirements for the capture of carbon dioxide from air, Chemical Engineering and Processing

De Jonge et al, 2019, Life cycle carbon efficiency of Direct Air Capture systems with strong hydroxide sorbents, International Journal of Greenhouse Gas Control

Democracy Now!, 2023, "I'm Not a Criminal... Enbridge Is": Charges Tossed Against Winona LaDuke & Others for Pipeline Action (video)

Paris Agreement, 21st Conference of the Parties, COP21, 2015

Goobie et al, 2022, Association of Particulate Matter Exposure With Lung Function and Mortality Among Patients With Fibrotic Interstitial Lung Disease, JAMA Internal Medicine

The Daily Climate newsroom, solution-focused journalism

Grist newsroom, solution-focused journalism

Kristina Marusic, 2022, Tiny particles of air pollution appear more deadly if from human-made sources, The Daily Climate (article)

Kroll et al, 2020, The complex chemical effects of COVID-19 shutdowns on air quality, Nature Chemistry (article)

Crystal Gammon, 2012, Pollution, Poverty and People of Color: Asthma and the Inner City,

Dipika Kadaba, 2017, Nothing to Wheeze At: Air Pollution's Disproportionate Effect on Poor and Minority Communities, The Revelator (article)

Center for Biological Diversity

Grist Creative, 2021, Clean energy can bring climate justice to communities throughout America, Grist (article)

Al Jazeera, 2012, Fracking in America (documentary)

Upayan Mathkari, 2013, Magnesium Sulfate (MgSO₄) Dissolving in Water Animated (video)

Chelsi Mueller and Helena Schmidt, 2023, Saudi Arabia's Neom Project, the Howeitat Conflict and Tribe-State Relations, E-InternationalRelations (article)

Rayhan Uddin, 2023, Neom: Saudi Arabia jails nearly 50 tribespeople for resisting displacement, MiddleEastEye (article)

UN Press Release, 2023, Saudi Arabia: UN experts alarmed by imminent executions linked to NEOM project, United Nations Human Rights Office of the High Commissioner (article)

Lylla Younes, 2022, Saudi Arabia has a new green agenda. Cutting oil production isn't part of it, Grist (article)

U.S. Congress Research Service Report, 2020, Carbon Capture Versus Direct Air Capture (article)

Lakey et al, 2016, Chemical exposure-response relationship between air pollutants and reactive oxygen species in the human respiratory tract, Nature 

Nathanael Johnson, 2022, Save the nukes?, Grist (article)

Oregon Public Broadcasting, 2023, Salmon People: A Native Fishing Family's Fight to Preserve a Way of Life (documentary)

Volts podcast by David Roberts about the technology, politics, and policy of decarbonization

David Roberts with guest Jigar Shah, 2024, Nuclear? Perhaps!, Volts (podcast)

DiGiulio et al, 2021, Vulnerability of Groundwater Resources Underlying Unlined Produced Water Ponds in the Tulare Basin of the San Joaquin Valley, California, Environmental Science and Technology (research article)

Sonya Remington Doucette, 2021, Hope is Not Optional, Bellevue College, Opening Day (video presentation)

K-12 Next Generation Science Standards (webpage)

Activating Prior Knowledge, Virginia Tech Center for Excellence in Teaching and Learning (article)

Salina Gray and Alexis Patterson Williams, 2020, Social Justice Issues As Phenomena (video presentation)

Phenomena and the NGSS, San Diego County Office of Education (article)