At the beginning of each school year I stress to my Honors Chemistry students that memorization will not get them very far in this class. As a chemistry teacher, I am all about understanding chemistry, not remembering it. BUT, there are a few facts that you really need at your fingertips — and I don’t mean accessible with your fingertips and a smartphone! One of those sets of facts is the formulae of polyatomic ions. For my students, that means a list of 25 polyatomic ions that they must know inside and out, backward and forward. After about a week of study, they are given a quiz that contains all 25 ions, either written in their word form or as a chemical formula, e.g., nitrate or NO3-, respectively. The students must retrieve the exact formula or name from their memories with no help from a word bank.
I realize that this might be a monumental, miserable task for many of my 15 and 16-year-olds. Some students will master the list simply because they’re good students and good memorizers and do whatever is asked of them, but I have a bunch of kids that will study only until they have a mediocre knowledge of the ions. Getting this latter group to know the ions brings the lyrics from that old Mary Poppins song to mind:
A spoonful of sugar helps the medicine go down
In the spirit of Mary Poppins, I coax my students along in their studying with a prize given only to those who score a 96% or better on the quiz. I take advantage of the fact that my students, especially the boys, are almost always hungry and looking for a good snack. But I don’t offer just any old snack; my prize is one they can’t buy in a store and can only get by acing my quiz: a delicious, home-made (and not from a box) chocolaty, chewy brownie delivered mid-morning when their hunger pangs are revving up. This catches their attention. The polyatomic ion quiz is clearly not an ordinary quiz. There’s extra reason to study.
I’ve been offering these brownies for most of my 19-year career; plus I publicly announce the names of those who win a brownie in our all-school morning meeting, so this quiz and its prize have become somewhat of a tradition at my school. In fact, my students know about the brownie quiz before the school year even starts and eagerly await their turn at winning one. The results tell it all: This year was like most of the rest: 46% of my students earned a brownie, and, better yet, the class average on the quiz was 91%!