Experimental Methods of Valency

Abstract

There are numerous experimental techniques used not only to identify and determine the geometry of molecules to varying degrees of accuracy, but also in some cases to provide values of such quantities as dissociation energies. These methods can be divided into two distinct types: (a) spectroscopic and (b) diffraction methods. Sometimes in the former method diffraction gratings are used to disperse the wavelengths of the radiation used, but the essential difference is that in spectroscopic methods we are studying the absorption or emission of radiation by atoms or molecules (in any phase), whereas in the diffraction method we are using the atoms and molecules (again in any phase) as the diffracting medium. Mass spectroscopy is another method for studying molecular structure, utilizing the separation of atomic or molecular ions of different mass-to-charge ratios in a magnetic field.