I suppose I am more aware of mistakes in this area as I have built and worked with Excimer lasers, but I am really disturbed by the 8 unshielded electrons. The mistake is not so upsetting but the fact that people adopt the mistake so easily in their learning, and you have to take a major journey.... just really yuk. http://lessonpeer.com/drhillteach/Theodore%20Grays%20Periodic%20Table%20Noble%20Gases.mp4