Physical Chemistry

How a Photon Is Created or Absorbed

Giles Henderson
Eastern Illinois University, Charleston, IL 61920

Robert C. Rittenhouse
Walla Walla College, College Place, WA 99324

John C. Wright and Jon L. Holmes
University of Wisconsin-Madison, Madison, WI 53706

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.

Investigating the Invisible: Attenuation of Radio Waves

In this Activity, students investigate properties of radiation using a handheld radio. Students compare the abilities of conductive and dielectric materials to attenuate or block, radio waves, and compare the attenuation of AM versus FM radio waves. The radio is placed inside different objects and students record which materials blocked or attenuated the waves.

Colors in Liquid Crystals

In this Activity, students investigate the relationship between temperature and composition and the reflected and transmitted colors of a common nanoscale material, the cholesteric liquid crystal.