Blogs

Unit Cell Modeling

unit cell models

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. 

Struggles with Bonding...Making it Simple...

Chemical misconceptions

I have always struggled teaching the concept of bonding. What is a chemical bond? Is it just covalent or ionic? What about hydrogen bonds? Are those real bonds or just attractive forces pretending to be bonds? If they are not official bonds, what do we call them? How about intermolecular forces? How are those different from salt crystals that attract to other salt crystals but are called ionic bonds? How about "electronegativity"? If there is a metal nonmetal compound but it is just shy of the "cut off" for the difference between polar covalent and ionic, what type of bond is it? Essentially, as I got confused over the years, this translated into confused students and rushing on to get to the next unit in an attempt to cut my losses.

The first PBL experience I facilitated was a flop.

My first big project my students engaged in during the 2013-14 school year was, at best, a mediocre experience and, at worst, a giant waste of valuable instructional time we'd never get back. I was at a new school and had a lot of goals I wanted to explore - further investing time into developing classroom culture, engaging students into taking more ownership in their learning instead of being passive recipients, pushing students deeper while meeting them where they were at - in short, developing my teaching identity in a context with a lot of autonomy. I had total teaching freedom.

 

Inquiry, "Sticky Water" and some great models...

Sticky Water Lab

 I just completed covering "ionic and covalent" bonding with my studenets. I wanted to bridge the gap to intermolecular forces. I found a great lab called "Sticky Water" from Target Inquiry - Grand Valley State.(link is external)  Before I continue, I have to provide "full disclosure". I spent three years with the Target Inquiry Program at Miami University Ohio (Project TIMU(link is external)). There is a lab called "Sticky Water" that was written  by a teacher in the Grand Valley State program. First, the activity focuses on just water, then ethane, then ethanol. 

Card Sorts... What to do next?.... and Happy Accidents...

Card sort

We just finished an introduction into ionic and covalent bonding. Somehow I wanted to try to figure out what they did or did not take away from the experience but because we just finished semester exams, I did not want to do another test or quiz. Instead, I tried a "card sort".

How Running a STEM Club Benefits My Classroom

ACS Chem Club

I run an after school STEM club that involves many projects and activities. Students build robots for FIRST Robotics, race RC cars, use 3D printers, and build underwater vehicles. They dissect specimens, and create biodiesel from vegetable oil. So why would I bring this up on the Chemed Xchange? Our science club does chemistry activities, we are an ACS Chem Clubs(link is external), but I think there are many other benefits to this kind of club. Here are a few: