Why is Chemistry so hard?

I’m channeling my frustration against my chemistry course towards an investigation of why it was so unrewarding. How much of it is because chemistry is difficult (whether to me or in general), how much was due to the awful professor, what specifically went wrong, and how can we fix it?

Philosophically, the goal of natural science is to make accurate, testable predictions (and explain under what circumstances and to what extent those predictions fail). This means that natural science must be just abstract enough. Too abstract and it detaches from the real world and becomes mathematics; too empirical and it gets too unpredictable and becomes social science. Chemistry is a natural science, certainly, because it has both theoretical and real components. The problem is that both of these are foreign and hard to grasp to students.

Chemical theory (any chemistry done on paper) has an innately high barrier to entry. There’s a lot of basic knowledge that has to be memorized, such as the symbols and names of different elements, charges of various polyatomic ions, naming and notation conventions of compounds, and so on. Some amount of memorization is inescapable, but that does not include the table of 150 species that I’m supposed to memorize for the final. (Contrast the physics teacher who on more than one occasion said that “this course is not an exercise in memorizing equations”.) Memorization isn’t a good use of my time, since this is repetitive information I could look up if I needed to in the real world. In fact, I could look it up on my phone if I wanted to, from almost anywhere in the world. Rote memorization is irrelevant and infuriating, and therefore educationally ineffective, in the twenty-first century. And for children especially, it’s boring, which means it won’t create the interest in STEM fields at a young age that we need.

Experts tend to forget what it was like to be newcomers. Chemists tend to use a lot of jargon without bothering to explain it. It’s easy to mix up chlorine and chloride, or atomic and molecular orbitals, if you don’t qualitatively understand how dramatically different they are. On the other hand, the notation borders on the pedantic: CS is carbon sulfide while Cs is cesium. (Although physics is often a worse offender in that regard.) Experts, having long since acclimated to these distinctions, don’t think to or don’t bother to explain them to neophytes.

On to empirical chemistry. I’ve never seen an atom. I don’t have the same intuitive feel for most of the species talked about in class, like phosphorus pentafluoride; I can’t even pronounce many of them. We don’t come into contact with many chemicals in our daily lives the way we encounter physics concepts like motion or heat. “Where do we get all these chemicals?” asked the professor one day to a room of blank stares. “You dig them up in salt mines!” Well maybe you do, but the rest of us come from suburban America with a suspicious lack of salt mines readily accessible. Chlorine gas seems as distant as WWI.

A physicist is comfortable with terms like “gravitational lensing”, metaphorically saying that a galaxy of billions of stars affects light the same way as a piece of plastic that you can hold in your hand. An insulator can be thermal, electrical, or acoustic, because even though the phenomena are different, insulating materials behave analogously.  All of physics is the same handful of concepts reprised endlessly, like a great fugue. The number of tools is small compared to the number of uses. In this way, physics is vertically structured, nested. Chemistry is sprawled out horizontally, at least at an introductory level. (I’m told that missing one lecture of orgo makes the next incomprehensible.)  The chemistry I saw was little bits of nothing. That applies to both the subject matter and the way it was taught to me.

Ah yes, the way it was taught to me. I bet that quite a bit of my enjoyment of physics and my dislike of chemistry is due to the teachers I’ve had. My chemistry teacher would often digress to a politics rant, or put handwritten (nearly illegible and unsearchable) notes on the part of the projector that wasn’t projected to where we can see them, or ask questions to make the whole class feel stupid for taking an “introductory course.” But the question of what makes a bad (or good) teacher is far more complex than I my ability to answer fully.

But I do have a piece of that answer, which is: build on what you know. Or perhaps, what the students know. Don’t require students to memorize information or equations that can be looked up easily. Don’t intimidate the students, but don’t coddle them either. Do use ideas familiar to the students, either from prior experience or earlier in the course.

Oh, and if the class average is a 66, you’re doing something wrong.

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2 responses to this post.

  1. This obviously won’t change the class, or the professor, but you might find some pretty good help with these online sources: http://lifehac.kr/gYQGB1
    And yeah, I took Chem in high school and college, and found them to be taught by (usually) pretty awful professors. For some reason, Bio and Physics are (in my opinion) harder, but taught by better professors.

    Reply

  2. Saved as a favorite, I really like your blog! 🙂

    Reply

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