When students are first introduced to the idea of radioactive decay, a large conceptual hurdle must be overcome. The thought that an object's age has no bearing on the chance it will "die" (decay in this case) on a particular day is completely at odds with biological notions of life and death. Through the use of a simple…

An activity supporting the PhET interactive simulation, Models of the Hydrogen Atom, has been designed and used in the laboratory portion of a general chemistry course. This article describes the framework used to successfully accomplish implementation on a large scale. The activity guides students through a comparison and analysis of the six…

The relationship between pH and the aqueous solubility of heavy metals is explored by considering the environmental impact of acidic mine drainage. Acid mine drainage is an important environmental concern in many areas of the United States. Associated with coal mining in the East and hard rock mining in the West, the acidity originates primarily…

An exercise is described that has illustrated the effect of various factors on [pi] backbonding to carbonyl ligands, where the students can view the molecular orbitals corresponding to the M-CO [pi] interaction as well as the competing interaction between the metal and co-ligands. The visual and hands-on nature of the modeling exercise has helped…

Encourages the incorporation into lecture of live experiments that can be predicted or interpreted with abstract models. A demonstration is described where the position of the predominant peak of 1,1'-diethyl-4,4'-cyanine iodide is measured in class using an overhead projector spectrometer, then predicted using the model of a particle in a…