OK, I shall be more specific...
First I'll clarify what elements I DON'T classify as unknown, based on the fact that I am a teacher and teach these basic elements to junior students: 1-20, Fe, Zn, Hg, Ag, Au, Pu, U, Pt, W, I, Br, Sn, Pb, Cu, Ti and elements that I sppose you could say were just as "famous". Most people have heard of all these so I don't think it'll make for an interesting article.
My demographic is the readers of
http://www.cracked.com. I aim to read about the elements you guys suggest and write something humourous about each. Each element, I reckon, will have the following sub-headings.
Why is it Cool?
Why you've probably never heard of it
Is a rich man's...
(This final section will be where I compare the element to a more common one..., you know, say I was writing about Sodium, I'd go into why it was a rich man's Magnesium)
(Actually come to think about it the title is worth revising, cause Sodium is well worth writing about, despite being uttered a lot, maybe, maybe not)
Anyway that's the general idea. Cracked has plenty of science articles, it's well worth a look.