Sort of, but not in context of their original usage. Vonnegut's Ice 9 predated the naming of the real Ice 9, and Dilithium in Star Trek is not Li2. But yeah, in general I agree about dilithium. It would have been better if Star Trek had chosen a different name.

Indeed. I like that in Babylon 5 they went with "Quantum 40".

SG-1 kinda has the same problem, when you learn that Naqada is 20 km from Luxor and Kelowna is close to where the show was filmed.

It's easy to imagine that Naqādah the place was named by the Goa'uld because it had something to do with Naquadah processing or experiments. The expository dialogue writes itself there.

Kelowna is more of a stretch, but I'm betting that someone in the writers' room said "Hey, we already had a Salish episode; if anyone asks, we could just say that some native spirits influenced the names on both planets!" Apparently those people actually were the first inhabitants of that area. So all they'd need to do is connect them to Langara!

Kelowna is just the name of the planet on which Naquadria is found, so it makes sense that it would be a place name.

And it's not like place names and material names are mutually exclusive. Silicon Valley is an example of a place named after an element, and Berkelium is an element named after a place. There are 26 elements are named directly or indirectly after places.

Someone, somewhere, always has to suspend disbelief about locations in movies and TV shows, especially TV shows. :)