The steps of Zn corrosion and ZnO formation using dry O-2 or O-2/water atmosphere were investigated in situ using an experimental and theoretical approach. The adsorption equilibrium and kinetics of O-2/H2O on Zn have been measured at different temperatures and relative humidities using a Cahn 1000 vacuum recording electrobalance. The amounts adsorbed on Zn are different in the presence or absence Of O-2. SEM-EDAX, XPS, and XRD studies have been performed at the surface for different times of reaction. A theoretical study using the extended Huckel method has been done for the adsorption/reaction of H2O/O-2 on Zn and on ZnO. A coherent explanation is presented for the initial steps of ZnO formation on Zn, for the steady state found for the ZnO growth, and for the experimental findings of the methods cited above. (C) 2004 Elsevier Inc. All rights reserved.