[en] Auger electron spectroscopy (AES) and flash desorption mass spectrometry have been used to determine relative saturation densities of C, O, H, and N atoms on (100)W from adsorption of O₂, H₂, N₂, CO, NO, and H₂O. From a previous direct determination of the O₂ density on this plane, densities of the other species were obtained. In the case of H₂, the only adsorbate for which there has been disagreement in the literature, a density of approximately 1.5 that of the substrate is found. For other adsorbates this ratio is close to 0.5 or 1.0. (Auth.)