If we’re going to cite songs, I should mention Tom Lehrer’s The Elements (clever flash animation version).
Toponyms, surely?
I always wish that I could remember the elements in their correct order, rather than in Lehrer’s. 
Now’s the time for that Paul Lynde line (said with a sneer) “Think yer smart, doncha?” Hell, I’ve lived my whole life surrounded by radioactivity. 
Toponyms are place names, not things named after place names. Eponyms are things named after people, so I combined the first three letters of both eponym and toponym to come up with epotope (the final E was added to make the last O long).