The history of the discovery, isolation, characterization, production and use of argon, krypton, xenon, helium, and radon is followed by an account of early attempts to react them with other elements. The use of the electron shell theory of valence to explain their inertness and the reactions of chemists to the production of xenon compounds is described. The presently know n compounds of xenon and krypton are listed, and the use of molecular shapes of these compounds as determined by x-ray crystallagraphy and electron diffraction to test theories of chemical bonding is discussed. Illustrations, a short bibliography, and a film list are included. (AL)