I've never read Superman books, except for the Death of Superman, so any knowledge I have of the Superman mythos is almost completely second hand. My question: is kryptonite supposed to be the noble gas krypton (Kr)? If so, why is it always a crystal if the freezing point of Kr is 115 K? And if krypton and kryptonite and the planet Krypton are not related, why are they named so similarly? The -ite suffix supposes an oxygen bond, but we all know group 8 atoms do not bond to anything, so is there an ultimate truth to the mystery, or is kryptonite an example of poor research? Thanks.

I'm no Superman expert either, but Kryptonite is basically rocks from the exploded planet Krypton (like meteorites, but more specific). Here's a page that talks about the known kinds from various Superman mythos.

As far as the actual gas krypton the only thing it has in common with the planet in Superman is the name (see last line of linked page). Most likely they picked the planet's name because it sounded cool, and didn't think any kid reading the comic would connect the name to the element.

Dude, it's a comic book.

If the element Californium (Cf) is highly radioactive, and has a half life measured in days, why is Los Angeles so crowded?

Now that doesn't make sense, Nick Danger. California the state was founded long before the synthesis of Cf. The planet Krypton was named AFTER the discovery of Kr. Big difference.

Should I have used Francium?

Maybe both Kryptons came independently from the same root word: kryptos, Greek for 'hidden'. Or maybe it was just to make the comic more realistic. There is already Mercury, Uranium, Neptunium, and Plutonium; Helium, Selenium, and Tellurium.

Don't believe all those different colors of Kryptonite. Post-Crisis DC world only has green. Even though in Superman/Batman it looks like red might be coming back.