Collision experiments with He 23S and Ne3P metastable atoms are described, giving the total collision cross sections of these atoms with He, Ne, A at thermal energies, also the absorption cross sections of resonance photons from the He, Ne discharges.The secondary electron yields from He metastable atoms and from resonance photons incident upon W, Mo, Pt surfaces flashed to 1700°C are compared with the yields from an unflashed Au surface, previously determined absolutely. The rate of rise of yield due to gas contamination is examined. The yields from the flashed surfaces are found to be distinctly smaller than Hagstrum's yields for low‐energy positive ions.