Not really about the Polyatomics

This week there was a good conservation about polyatomic ions in #chemchat. There was quite a spectrum of responses. On one end, several teachers required their students to memorize all that were likely to come up in the course. At the other, some teachers just provided a list of them whenever students might need them. In my totally non scientific polling, it seemed that most people ended up asking their students to memorize around 10 basic polyatomic ions.

But in the end, I don’t think this conversation was truly about polyatomic ions. It was much more about our concepts of what chemistry is as a class. Some treat chemistry more as a natural history class. This is where I started out as a teacher. As a true chemistry nerd, I find the history and development of chemistry fascinating. When my students get to KMT I tell them about the arguments and even fights surrounding whether God could exist in Boyle’s vacuum camber lead to the founding of the Royal Society in England. But is this really relevant to my students??? Polyatomic ions just became part of a larger story of the development of our understanding.

Then others seem to treat chemistry more a foreign language class. Where students memorize vocabulary, the grammar of bonding and the syntax of chemical equations. This is often done with a loose connection to laboratory science through cookbook labs aimed to support content knowledge. In this case, polyatomic ions become an important part of speaking the language of chemistry and breadth is favored over depth.

The third approach come through modeling. In this, content knowledge is seen as a primary to understanding and predicting natural phenomena. The foundation of this approach is to teach students how they can explore our natural world using scientific method. There are several core concepts of chemistry that are emphasized with the hope that they reveal more about how the world works. Here’s polyatomic ions are just a conceptual component as depth is favored over breadth.

As I develop as a teacher, I have to ask myself why do I teach chemistry? Why would I teach a history or a language to students who will never use it? I had two years of Spanish and two years of Latin during middle school and high school. Now I’ve found little use for either in my lift, but I can say that the linguistic focus of my Latin teacher has cropped up in my life in many unexpected ways. And I can see how this may happen with my chemistry students. While I do teach at a rigorous college prep high school, I know that the majority of my students will not take another chemistry class after mine. So I have to ask myself will it be more important for them to understand the particle nature of matter or know the formula of a phosphate ion . .

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One thought on “Not really about the Polyatomics

  1. Interesting take on the recent #chemchat. Having arrived to the party late, I had missed most of the conversation you are referencing. And, like you, I find the history & very human foibles (like Arrhenius blocking Mendeleev’s Nobel prize) as fascinating as the content itself; and, likewise realize my job is not to indoctrinate students into Chemistry.
    But I think it’s a mistake to separate a specific particle, like phosphate, from the general goal of learning about particles; not just because specifics are more memorable than generalities, but because it presents only part of the story. After all, Chemistry is the story of specific chemicals and how those specific chemicals interact. Ira Remson’s story for example, “While reading a textbook of chemistry I came upon the statement, “nitric acid acts upon copper.” I was getting tired of reading such absurd stuff and I was determined to see what this meant.” This is the point of Chemistry to me: of equal importance are the macroscopic observations, the particle nature and changes associated, and the symbolic presentation. Without all three, the Chemistry presented is incomplete and certainly not memorable. Plus, phosphate in Cascade is why the dishes get white-washed in the dishwasher if you have hard water.

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