Balancing Equations with Molecular Models

molecular model kit

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”.

Time required: 

50 minutes

Olympiad Laboratory Challenge Part II

For my students and me, the AP Chemistry exam does not mark the end of the school year. Once the AP exam is over, my students are exhausted but our class continues to meet for three more weeks. Each year we complete a qualitative analysis lab, but this year we finished earlier than I anticipated. For the first time all year, I have the luxury of time.

Time required: 

45 minutes or less

An Unexpected Source of Inquiry-Based Lab Practicals


Each spring my Local Section of The American Chemical Society (ACS) hosts a rigorous two part exam as part of the selection process for the The International Chemistry Olympiad (IChO)  IChO is an annual international competition for the world’s top chemistry students. Each year, nations from all over the world will send teams of four to compete for top honors.

Time required: 

45 minutes

Chemistry Thus Far . . .

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.

Time required: 
Timeline for This Activity:
  • This activity can be done at the end of each unit, before a semester exam, or when students return from an extended break


Bell Ringers for Conservation of Mass

bell ringer 1

This is my first year of using Modeling Instruction in my chemistry classes. During a fit of productivity, I created some bell ringers for unit one, which is partly about conservation of mass. I hope you will find them useful. Comments are welcome. I would love to see what others might be using.

You can access the bell ringers below. They are part of the "student document".



Time required: 

Approximately 5 minutes per class period.