It was the empty terrible feeling in the pit of my stomach at 9:30 at night that really bothered me as I am wading through the stack of papers that I was grading. I had the students do experiments, worksheets, I lectured and there was homework. Some of the students could “do” what I thought was science. They could calculate the answer. They could balance the equation.
A quick search on Amazon for a package of 144 ping pong balls and a trip to the arts and crafts store for paint, magnets, and glue and I was ready to start making my own class set of model kits.
I am a very firm believer that the world of physical science can be visualized and is an excellent medium for teaching students to model and to picture what happens at the molecular level. The first topic we decided to explore was balancing chemical equations. This seems like such a simple topic to chemistry teachers but I have found that it can be quite challenging for many of my inner city students. The first thing they ask me for is a list of rules that they can follow. We can discuss the problems of algorithmic teaching in a later post! For the time being let’s talk about how to get students to understand why they need to balance equations and discuss what we can call “Conservation of Atoms”.
If you look at any chemistry textbook, you will see Lewis structures introduced long before electronic and molecular geometries. This makes sense since you need Lewis structures to determine molecular geometry. Unfortunately, research has shown that students often do not recognize that the purpose of drawing Lewis structures is not to create the structure itself but to use it as tool to understand the properties of the molecule (Cooper, Grove, Underwood & Klymkowsky, 2010).
This past summer our conversations turned to, “How can we improve our instruction to try and prevent the initial misunderstanding?” We had all read Dorothy Gabel’s article Improving Teaching and Learning Through Chemistry Education Research: A Look to the Future. We were intrigued by the author's description of the three fold system of representing concepts in chemistry.
Using a whiteboard or poster paper each group of students creates their interpretation of the model thus far based on a content unit they are given.
The American Modeling Teachers Association (AMTA) website is the official source for information on Modeling InstructionTM (MI). Whether you are an experienced Modeler or simply interested in learning more about MI, I encourage you to visit the newly redesigned site and check out the available resources.
I started thinking about how integral the storytelling was to the curricular choices I made in my classroom. I realized that I had shared some of my experiences as a Modeler and a few of the activities we use in our classrooms, but I have never described the order of topics. So, this blog is titled “The Model So Far…” I hope it gives you an idea of the journey we take each year as the students uncover evidence and construct models along the way.
This is a Chemical Reactions lab that I modified to meet NGSS guidelines.
Through a series of three blog posts, I’d like to share my thoughts about these scientific practices and how we might communicate about these practices to middle and high school students. I’d love to hear your thoughts along the way! Let’s start with model building…