Developments in the title field have been greatly motivated by the studies of transactinoid elements; selected experiments and their results are presented for visualization. Primarily, the book is about the physico–chemical basis of the experimental methods and techniques which are or can be used for compounds of all heavy metals; about evaluation of the desorption energies from the original gas–solid chromatography data; and about concepts and approaches which allow to estimate bulk properties of the compounds even from experiments with a few short–lived atoms. The book attempts for the first time critical discussion of the state of art from a coherent point of view to help better understanding. It was written both for the newcomers to the field and experts, its goal is also to stimulate wider use of the advantageous gas phase techniques for common elements.