In an effort to better understand my high school students' knowledge of what is happening during phase changes, heating curve calculations, and the ever popular can crush demo, I run them through a series of activities. First, I ask my students "What Temperature Does Water Boil At?"
Students will build models of isomers while the instructor walks around from station to station to critique the models. If the model is incorrect, the students rebuild until they get it right. The paper that accompanies this assignment is very easy to grade.
In this "Pick" I'll briefly describe how I use the ChemDraw iPad App for creating structures for my teaching. I also provide a link to a tutorial where I share some tips on how to get started using ChemDraw on your iPad.
Atomsmith works really well on Chromebooks and other platforms. Students can manipulate molecules, add water, do experiments, heat solutions and examine intermolecular forces all on the particulate level. Another nice feature is the "Experiment" section. There are a number of guided activities, usually never more than a page or two. I have found them to be great supplements for activities, experiments and demonstrations.
In a previous post I talked about an equation balancing lab that I have been doing with my students involving building molecular models. This time I would like to focus on another lab that I have developed for my model kits.
Here is what I told my students as we were studying gas laws. I have a bag of potato chips at see level and then I go to Denver where the pressure is less? What happens? Draw and build a model on your whiteboard.
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).