first-year undergraduate

Clarifying Electron Configurations

We’ve all seen and use the so-called Aufbau Diagram. It is a mnemonic used to remember the order of “filling” of atomic orbitals during the construction of the ground state electron configurations of the elements. The presentation of this diagram is largely disconnected from any physical meaning. Here’s what we tell our students: “Memorize the diagram, learn to use it, and you’re guaranteed to get the right answer.”

Conversations, Confessions, Confusions (and hopefully some Clarity) on Electronic Configurations

A complete understanding of why each element has a particular electronic configurations is a very complex subject. Even so, some confusion regarding the electronic configurations of the elements may be alleviated by looking at the physical properties of the electronic orbitals.

Blending a Periodicity Unit

Previously I wrote about taking part in a district-wide high school blended learning pilot. You can read about it here. I received my Chromebook cart near the end of February/beginning of March. A little late but just in time for the periodicity unit I was planning as a blended unit. The following is a breakdown of how I designed the unit.

Not All Periodic Tables are the Same?

Upon sharing my array of apps with some future chemistry teachers, they asked why so many Periodic Tables? My response was “Well not all periodic tables are the same”, upon which was followed by several blank stares...Let me explain: I currently have the following periodic table apps loaded on my iPad...

The Art of the Chemical Demonstration

One of my favorite things to talk about with my colleagues is the use of lecture demonstrations in teaching. There seems to be a push in my district to stop using chemicals whenever possible and get to computer simulations and video in place of wet chemistry. I don’t think they are thrilled with me since I can’t envision ever taking the chemistry out of chemistry.

Colligative Properties in Real Life

This year in the midwest United States, winter has been a fickle friend. I haven’t seen the same amount of snow or ice as in recent years, but I still made sure I was prepared for it at our home. I went to my local big box hardware store in December and contemplated buying rock salt (NaCl), and NaCl/calcium chloride mixture, or just calcium chloride. Growing up my dad had switched entirely to calcium chloride because it was less damaging to the brick pavers leading to our porch and backyard. In fact, calcium chloride is generally much safer toward plants and soil than NaCl. Even though calcium chloride is much more expensive than rock salt (it was about twice the cost for 10 pounds more), that what’s I chose. Why?

Relative Reactivities of Metals

Last winter I watched a webinar put on by ACS and AACT called "NGSS in the Chemistry Classroom." As a result of watching that webinar, I took an activity that had NGSS Science & Engineering Practices (SEP) integrated into it and tried it out in class. In this activity, students are required to develop their own procedures and data tables.