We are investigating the interactions of hyperthermal energy (few to several hundred eV) atomic ions with metal surfaces, focusing on ion-surface charge exchange processes. For Li+ scattering from alkali-covered Cu(001), we have measured branching ratios for Li+, Li- and ground- and excited-state Li deg in the scattered flux. These results are interpreted using a state-of-the art multi-channel charge transfer code developed by Brad Marston. Using this code, we have gained important insights into the dynamics of multi-channel charge transfer processes. We are extending these studies to higher-lying excited states of Li, excited state formation in Na scattering, and multi-channel charge transfer in 0 scattering. For Na+ scattering from clean Cu(001) we have observed trajectory-dependent charge transfer in which the charge transfer probability is dependent on the collisional history of the particle; evidence is found for modification of the neutralization due to defect formation that can occur in certain types of collisions with the surface. We plan to study trapping behavior for hyperthermal energy alkalis and oxygen incident on metal surfaces. Charge transfer, Hyperthermal energy ion scattering, Classical trajectory simulations, Atomic and molecular ions, Hyperthermal oxygen beams, Neutral detection, Scattering dynamics, Energy transfer, Particle trapping.