atomic structure

Analogy Experiment—Projectile Pennies with Rutherford

Atomic theory is a common topic throughout any introductory chemistry course. It is likely that Rutherford’s gold foil experiment gets at least some attention in your course. I have used a simple activity that gives students an opportunity to replicate Rutherford’s experiment through an analogy experiment that may allow for easier conceptualization of the experiment itself and provide additional support for model development.

Chemical Thinking Interactives

As part of a two-week Chemistry Modeling Workshop™ in Houston, TX, I had the opportunity to read the by Vicente Talanquer of the University of Arizona. I researched Dr. Talanquer and discovered he created a collection of simulations called Chemical Thinking Interactives (CTI). These digital tools illustrate many chemistry topics with a focus on the particulate nature of matter.

Figuring Out Electron Configurations

After spending the start of the year using a modified version of the Modeling Instruction curriculum (density and physical properties, followed by gas laws, followed by energy and phase changes), we don’t actually start talking about what’s inside atoms until December. I love that by this point students are already familiar with some of the habits of mind needed to reason abstractly about atoms -- thinking proportionally, explaining macroscopic observations at the particle level -- and we are ready to layer on both more abstraction and the symbolic level. By January, we are ready to explore electron configurations.

The World's Biggest Flame Test....

Most chemistry teachers I know do flame tests with their students. It ties in well with many topics, is colorful and the kids enjoy seeing the colors and burning stuff. There are many applications. For years I always mentioned that astronomers use the idea of the flame test. They simply look at stars and examine the spectra from the light of these stars. They then match the spectra with the elements and then they can see and infer what elements are millions of light years away. I always mentioned this but never was able to demonstrate it. 

Extension Activity with Isotopes Matter

After receiving positive feedback from Peter Mahaffy, the IUPAC project co-chair of Isotopes Matter, I decided to add an additional component to the original isotope assignment I posted. The second component of the assignment focuses on the applications of both radioactive and stable isotopes using the interactive IUPAC periodic table.

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.

The Search for the Final Element

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.