Abstract
Chemisorption of oxygen on Al and Mg was found to cause photon emission with a probability of about 107 per molecule. The photon intensity was continuously recorded for oxygen exposures 108-101 Torr sec. The intensity is closely related to the chemisorption rate and a rate <103 monolayer/sec was easily detected. Spectral analysis revealed broad emission bands with maxima at 5100 and 5900 Å for Al + O2 and at 4700 and 5600 Å for Mg + O2.