At Imperial College, staff from the mathematics and chemistry departments have set up computer-based "Mathematics Laboratories"
for first year chemistry undergraduates. We've provided several types of activity in these laboratories, but one of the most
important kinds involves students setting up and studying models and simulations of chemical conditions and processes. All
our simulations are implemented entirely in *Mathematica*. *Mathematica* works for us as simulation and modeling software because it allows us to be open in our approach to design. All the code
that is used to set up and run the simulations is visible to the students, and indeed we require them to engage with it directly.
The relationships between the underlying mathematics, the chemistry that is being modeled, and the computer code that implements
the model can be explicit rather than hidden. Students can be encouraged to adopt a critical attitude toward mathematical
models and to develop their own ideas and approaches. On the other hand, *Mathematica*'s power and range enable us to set up fairly realistic and uncontrived problems, and to place some of the mathematical elements
of these problems firmly in the background if we choose. I illustrate these strengths of *Mathematica* using the example of a series of assessed problems. These concern the forces between ions (modeled as Newtonian point charges)
and the chemical dynamics to which these forces give rise. I show examples of closed and open-ended tasks, and present excerpts
of students' work on these tasks.