The interaction of hydrazine with evaporated metal films of Fe, Ni, and Cu has been investigated in the temperature range 243-393 K. Dissociative chemisorption of hydrazine occurred on Fe and Ni films at 243 K with liberation of NHâ, Nâ, and Hâ gases. Adsorption on Cu film at the same temperature was molecular and a significant fraction of the adsorption was reversible. Two different mechanisms have been suggested for the adsorption and the subsequent formation of the decomposition products. Ammonia was the main gaseous product of hydrazine decomposition on the films at all temperatures. The desorption of the products was more extensive in the case of Ni film as compared with the other two metals. The activation energy (E/sub a/) of hydrazine adsorption as well as the pre-exponential factor (A) in the rate equation remained independent of extent of adsorption. The relationship which was found to exist between the values of log A and those of E/sub a/ indicated the operation of a compensation effect in the hydrazine adsorption on the films. Copper film was found to have a greater capability for hydrazine adsorption than the other two films. The geometric requirements for appropriate hydrazine adsorption on this metal are probably more satisfied than on the other two metals. 27 references, 6 figures, 4 tables