Ozone
Well, most people I talked to about ozone knew of the layer in the stratosphere, how it protects us from UV rays, how it is thinning as a result of pollution. My husband attempted some stats- miles from Earth, % of atmosphere. He was off quite a bit, but he was a good sport for playing! Fewer comments were made about the "bad ozone" in our troposphere.
Review
The Atomic Properties Menu is a wonderful tool for learning all about electronic structures, ionizations, affinities, etc. It's step by step (in fact the author will encourage you to go back- or he'll offer up more links- until you're comfortable with particular concepts.) Equally helpful, he'll assure you when something doesn't have to be (or can't be) fully understood or explained.
Great resource!