How G.N. Lewis reset the terms of the dialogue between chemistry and physics.
While quantum physics provided a mathematical framework for understanding the valency of chemical elements, to make use of these mathematical equations required approximations based on chemical experience. To better understand how this establishes limits to the presumption that chemistry can be derived from physics, this paper starts with the warnings in Coulson's widely read text, Valence, as to why there are pitfalls in the interpretation of what "valence" accomplishes. He directs some of these concerns back to Pauling's earlier text, The Nature of the Chemical Bond. Both Coulson and Pauling are aware that quantum theory's ability to approximate the energetic stability of chemical systems is of use to chemistry only if it can be correlated with the molecular structure that results from chemical bonding. While this may now be routinely expected, it was a struggle to see that this was the challenge chemistry posed to physics-and this achievement they both attribute to G.N. Lewis. Until the more mature forms of quantum mechanics arose in the 1920s, Lewis was skeptical that the dynamic models of the atom posed by Bohr could meet this challenge. How Lewis formulates this challenge initially in 1916 and then in his longer work, Valence and the Structure of Atoms and Molecules, will be examined.
Bogaard
Paul A
PA
Department of Philosophy, Mount Allison University, New Brunswick, Canada. pbogaard@mta.ca