Atomic and Molecular Structure

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.

Building Atoms: One App at a Time

In my high school chemistry class, a unit we cover is that of atomic structure. In particular, given an elements symbol, mass number, atomic number, and charge, the objective would be for the student to determine the atoms number of protons, neutrons, and electrons. I have several apps/program suggestions that can be useful for this purpose.

JCE 93.01—January 2016 Issue Highlights

Kick Off 2016 with Volume 93

The January 2016 issue of the Journal of Chemical Education is now available to subscribers. Topics featured in this issue include: examining the flipped classroom; central ideas in chemistry & teaching; chemistry, art, & color; expanding student understanding; improving student communication skills; analytical chemistry & instrumental analysis; experimenting with natural products; undergraduate research experiences; educational resources; from the archive: using nonfiction to teach.

JCE 92.11—November 2015 Issue Highlights

Educational Opportunities and Challenges

The November 2015 issue of the Journal of Chemical Education is now available to subscribers. Topics featured in this issue include: materials science; polymer chemistry activities; green chemistry; biochemistry in the laboratory; research on student attitudes and the transition from high school to college chemistry; assessment; computer-based learning and computations; from the archives: chemistry YouTube videos.

JCE 92.06—June 2015 Issue Highlights

Extending and Deepening Student Understanding

The June 2015 issue of the Journal of Chemical Education is now available online to subscribers at http://pubs.acs.org/toc/jceda8/92/6. This issue includes articles on curriculum; assessment; inorganic chemistry; investigating galvanic cells & exploring LEDs; atomic structure; nanochemistry laboratories; physical chemistry in the lab; synthesis.

 

Representing the Macroscopic, Particulate, Symbolic, & Real World Representations of Chemical Reactions.

 Last year while attending the Biennial Conference on Chemical Education at GVSU I had the opportunity to hear a talk that showed a video of a chemical demonstration showing the burning of magnesium metal.  We have all seen many of these videos (thank you YouTube) and probably have performed this demo for our own students many times.  During the video it may have been represented with a chemical equation followed by the students being asked to balance the equation or maybe even predict the products.  Although the use of video including the showing of the equation nicely represents the macroscopic and symbolic representation, what was so unique about this particular video is that it also included the particulate representation embedded on top of the video of the demo.   This was the first time I had seen the particulate level representation done like that and so I was intrigued in wanting to find more of these representations.  

Flame Tests: Which Ion Causes the Color?

In this Activity, students perform simple flame tests using eleven commercially available compounds, cotton swabs, and a Bunsen burner. They then determine whether the cations or anions in each compound are responsible for the flame test colors. This Activity introduces students to flame tests in an inquiry-based manner.

Turning on the Light

In this Activity, students investigate the luminescent properties of common items such as glow-in-the-dark stickers, wintergreen-flavored hard candies, and a chlorophyll solution made from spinach leaves. After making observations, they use a flowchart to categorize the luminescent items as fluorescent, phosphorescent, or triboluminescent.