Knowledge Bank

Several emission continua were observed, in a transformer discharge of ($A+O2$), in the ultraviolet and vacuum regions. Approximate wavelengths of their peaks are 1490, 1840, 2100 and 2315 A. When krypton was used instead of argon, most of them showed a slight shift in wavelength at their peaks, except one at 2100 A. But, with xenon, all others disappeared completely except the longest at 2350 A, which also was observed by $Herman.(1)$ In consideration of the experimental conditions, these are probably due to the $O2$ produced by transitions from upper stable states to unstable lower states.