“chemistry is so hard”

“Chemistry is so hard.”

“Did you understand chemistry right away when you first learned it?”

“I don’t understand how you can teach chemistry.”

We just had our Unit 5 test, which was double replacement reactions/solubility, stoichiometry, and equilibrium. It was a long test. Most of my students didn’t finish it. And I heard (for the first time in my teaching career) that students cried after they left my classroom. I let my B day students see their exams yesterday and one student nearly broke into tears at the score. At least one other student refused to even open the exam.

It was admittedly a long exam. And I don’t really like teaching stoich at the end of the year (last year it came during Unit 3, which was the end of first semester). This year, our stoichiometry unit coincided with AP exams (particularly AP US History). My students who aren’t in APUSH had a huge project in their Honors US History class. Adding double replacement reactions and equilibrium to stoichiometry also just made the unit enormous and unwieldy; I’m honestly not sure why we decided to do it this way.

We met yesterday as a chemistry team to rework the curriculum map. I felt really strongly about cutting the units down a bit. A colleague very helpfully put the major topics on small strips of paper and we literally moved them around yesterday.

Overall, I think this sequence will work better. I think it will be better to break things up more. And another colleague yesterday suggested that for sophomore chemistry, maybe we don’t need to layer so many things with stoichiometry. Because the calculations are killer for some of my students. And I have to say, I agree. This unit test left me wondering- why should a student’s math ability dictate whether or not they can pass my class or whether they get a C or a D in my class? Does the ability to solve limiting reactant problems actually demonstrate a deeper understanding of chemistry?

I really liked last semester, because we spent so much time on the particle level and trying to connected it to the macroscale and symbolic (the vertices of Johnstone’s triangle). (I will admit though, I’m a bit ambivalent about teaching electron configuration and the quantum model of the atom. Do they really need that at an introductory level?)  I love Modeling Chemistry because of the emphasis it places on that conceptual understanding, and I’ve been able to convince coworkers to use aspects of it (without necessarily calling it Modeling) in their classrooms too, which is always a win.

I struggle with our curriculum map because it seems so broad. One colleague was advocating for teaching the actual ideal gas law (PV = nRT). In my opinion, that’s often just more math and conversions (convert between bars and atmospheres! Celcius and Kelvin! Torr and atmospheres!) We added in gas relationships this year, which I think was helpful in helping students understand the particle behaviors of gases, and I’m ok with leaving them at that. (We did agree that ideal gas law as the math wasn’t important enough to add back in. Kinetic molecular theory? I’m there, all the way.)

Another colleague really wants to teach electrochemistry because it’s so cool. And yes, it’s cool. It might be nice for students to know how a battery works, but do they really need to know how a battery works? And then, are we expecting them to write half reactions and work with the Nerst equation and all that? Electrochem remains at the end of the year, unless we decide (the following year) to bring it in with reaction types.

There is so much math in chemistry. And I love math, and I think math is beautiful and useful and awesome. But for high school sophomores, I wonder if it’s enough of a cognitive load to try to figure out what’s happening on the molecular/particle level. Trying to also connect that to math adds another layer that causes a lot of struggle for some students, and I don’t know that it’s fair to them.

So here’s the conflict as I see it – either teach less math in chemistry, or teach less content and give them more support to understand the connection between math/symbols, their observations, and what particles are doing that explain all that. I would vote for the latter, but I think the rest  of my course team would find that frustrating. So instead, our curriculum map remains about the same length as always, and we’re usually scrambling to cram everything in (or maybe that’s just me).

It’s a challenge and a struggle. The chemistry class I teach definitely moves at a slower pace than the accelerated course I took as a high school sophomore. And a part of me is sad that they don’t get to see “all” of chemistry, but the rest of me is realistic- when does the calculation of Gibbs Free Energy help in “real life”? I want them to learn how to think critically and learn a bit more about the world around them (we’re made of atoms! How atoms behave explain just about everything if you really want to get into it.), but do they really need the depth that I learned chemistry at in high school?

I don’t want to teach chemistry the way I was taught just because “that’s the way that worked for me, so it must continue to work.” Because it didn’t work for a lot of people. My students went slowly on the unit exam because so many of them were doing all the dimensional analysis as individual proportions. And I’m totally ok with that because it better demonstrates (to me) a conceptual understanding of why they’re doing each step that they’re doing. But those individual calculations are much slower than using a “mole map” or other foldable to figure out the calculations and powering through them. Often adults admit to me that they didn’t really understand why they were doing what they were doing with dimensional analysis until later in college chemistry (if at all). So why do we teach students to blindly follow algorithms that make no sense to them?

I want to challenge my students, I want to show them that the world around them, even things too small to see, are understandable, but I don’t want to set them up for failure (however I might joke with them that my job is to make them miserable). I’m feeling discouraged this weekend because I spent all last week dealing with stressed out students and trying to help them get a last minute understanding of what is happening, and I feel like I failed them on this unit test. Even though I spent the last 7 weeks holding weekly morning review sessions, I had an extra session on limiting reactants during our in-school tutoring time, I posted tons of extra practice, a screencast on how to solve these problems, and all the analogies I could think of with cooking, recipes, etc., on limiting reactant. It was limiting reactant that seemed to be the major stumbling block on this unit exam. Really, I’m just tired and worn out right now.

All of this just leads me to the question (which I’ve had before, but perhaps not articulated in this space) of why do we teach high school chemistry? A friend (who is not an educator) was genuinely wondering if it would be better to find out what students are really passionate about and then let their high school experience be more focused, rather than forcing students to sit through prescribed subjects that they don’t care about. He spoke from his own experience, where sitting through calculus was not really useful or productive for him. While I think there’s some problems with pushing kids to find a “passion” (as better articulated by this NYTimes blog post on passion in kids), I do wonder about the potential for real vocational education. I can see value in educating students with real life skills and for specialized professions that don’t need a liberal arts college degree, but I worry that it will result in more tracking and more segregation/stratification in society.

Some of my colleagues justify curricular and instructional decisions “because that’s what they need for college.” Why is that an appropriate reason to teach what we teach and the way that we teach it? Do my students really need to know the quantum mechanical model of the atom and how to write out an electron configuration? True, there are places where concepts I learned in chemistry are useful in every day life. Dimensional analysis and conversions are actually incredibly practically useful, but it’s the conceptual understanding that’s helped me more than memorizing how to set up a problem. So really, a deeper conceptual understanding is (in my opinion) better than just memorizing a bunch of algorithms and formulas, but the students want me to teach them THE method to solve the problem. It takes much longer to develop a deeper conceptual understanding of what’s happening, and I would love to take the time, instead of rushing through the content and feeling like I’ve failed my students because they tanked the unit exam.

I wish that I had time for some deeper conversations with colleagues abut why we teach what we teach, but most days there’s barely enough time to discuss what’s happening that day or what happened yesterday. So instead, I’ll just leave this braindump here. If anyone has suggestions, ideas, comments- please, let’s start a conversation.

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