modeling

Representing Molecules

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.

Balancing Equations with Molecular Models

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”.

A Look Into My General Chemistry Reactions Unit- Supporting Students with Making Connections among the Nanoscopic and Macroscopic

Organic chemistry was when I fell in love with chemistry. Also known as Chem 210 at the University of Michigan, it was the first time I actually started to connect what was going on at the nanoscopic level to the macroscopic world. Since then, I’ve been hooked.

 

A different way to look at heat and energy....

Each year we work on specific heat of materials and the heat of fusion of ice. These are two labs that are typical for most chemistry classrooms. Most of the experiments involve a simple calorimetry experiment that uses a styrofoam cup and provides generally good results. There tend to be a couple of key ideas with all of these experiments.

Rethinking Stoichiometry

Stoichiometry is arguably one of the most difficult concepts for students to grasp in a general chemistry class. Stoichiometry requires students to synthesize their knowledge of moles, balanced equations and proportional reasoning to describe a process that is too small to see. Many times teachers default to an algorithmic approach to solving stoichiometry problems, which may prevent students from gaining a full conceptual understanding of the reaction they are describing. 

Unit Cell Modeling

This year my students experienced something a little new to them on the Chemistry Olympiad. It was a question about the crystal structure of a mineral. I have not been teaching the “unit cell” concept in great detail and started to reevaluate my unit on liquids and solids. This question has been appearing on the semifinal exam of the Chemistry Olympiad for a few years but not the local exam until this year. I actually like it when something like this happens. It allows me to reevaluate what I am teaching in class, provides me an opportunity to learn new things, and brings new material into my curriculum. 

Blended Learning Pilot: #1

Last year, I researched and practiced what I thought to be "flipping the classroom". But, now that I am taking part in a district-wide "High School Blended Learning Pilot", I can say that I was attempting blended learning early in my teaching career. You see, the flipped classroom is really a small subtype of blended learning. So, the goal of this post is to define blended learning and share what my professional development has in store for me during this academic year.

Solubility and Models

First, I had my students examine the conductivity of a puddle of water the size of a nickel. They checked for conductivity. Then they took a very small amount of sodium carbonate and a fresh puddle of water and pushed in a few crystals from the side.  You can still see the crystals in the water but it tested positive for conductivity. They had to explain this. They did the same with a fresh puddle of water and a few crystals of copper (II) sulfate. Again, it tested positive for conductivity but they could still see the blue crystal. Finally, they started again with another fresh puddle of water, pushed a few crystals of sodium carbonate on one side and on the opposite side they pushed in a few crystals of copper (II) sulfate.  After waiting five minutes, a solid dull blue precipitate formed in the middle.  Also, the drop tested positive for conductivity.