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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.
We had just had some snow days and I had the feeling that I was getting behind. In one class we were approaching the topic of orbital diagrams and electron configurations. I was tempted to just say, "Here are the notes." Sometimes there is nothing wrong with that. This time, something was eating at me. Instead I picked a POGIL (link is external) from the "High School Chemistry" (link is external) book that presented the ideas through guided inquiry.
The new IB curriculum includes compound identification using NMR, IR and Mass spectroscopy. My current high school lab does not have any of these available. And that's no surprise, given the cost of these machines is far out of our budget. And while some of you may be lucky enough to have a connection to a local university or college, for the rest of us what are the options when it comes to teaching spectroscopy?
Have you ever wondered what is the theoretically largest possible value for the atomic number of an element? Using some introductory physics and algebra, you can get your students thinking about this idea.
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.
As a new semester begins, I am excited again. Starting fresh, introducing new people to the amazing world of chemistry, and putting my newly edited labs to the test! In addition, another instructor is trying my labs.
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.
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 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.
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".