“Chemistry has a position in the center of the sciences, bordering onto physics, which provides its theoretical foundation, on one side, and onto biology on the other, living organisms being the most complex of all chemical systems” (Malmström et al.). Thus begins a recent essay on the development of modern chemistry. Philosophers have long wrestled with how best to describe the exact relationship between chemistry and physics. Is it an example of a classic reduction? But before we ask whether chemistry could in principle be derived from physics, there is a prior question: How well integrated is the science of chemistry itself? This chapter argues that although there is a coherent explanatory core within chemical theory, contingency plays a larger role than is usually recognized. Furthermore, these phenomena at the boundaries of traditional chemistry education are where some of the most important current research is occurring. I will first adopt a quasi-historical approach in this essay, including anecdotes from my own educational trajectory. I then briefly discuss how our current understanding of the explanatory structure of chemistry should be reflected in education today. The professor of quantum chemistry at the University of Illinois in the 1950s told us a story from his PhD defense. His director, Linus Pauling, walked into the room and said something to this effect: “Well, Karplus, you’ve done a bunch of calculations on the hydrogen molecule ion (H2 +). Very nice. But you claim to be a chemist. So please write the Periodic Table on the board for us.” Who knows exactly what point Pauling was actually trying to make, but it reminds us of this basic point. The periodic table with its horizontal and vertical trends is still the basis of the classification of enormous amounts of information about the formulae and properties of chemical compounds. Mendeleev would not have understood talk of strontium-90, but he would have realized immediately that this product of nuclear testing would enter the body in a manner similar to calcium.
Isotopes Matter