A friend of mine is very good at surplus auctions... That would be where the majority of the stuff which gets described on these web pages comes from. That and mail order... (At least when they are willing to sell it to mere mortals, but thats another rant.)
Anyway, he got a bottle of xenon. Its probably mostly empty. Especially since it was filled in 1983. (This is being written in December 2004) Its not dead yet.
So, I filled a balloon with it, just to see what would happen. Then I was going to run some electricity through it, to see if anything more interesting would happen. Unfortunately the power supply I was hoping to use turned out to be dead.
However, the balloon itself was mighty bizarre.
I suppose this is stating the obvious. Like how two beams of orthogonally polarized light do not form an interference pattern (That was not obvious, until just recently...). But Xenon is denser than air. So, the balloon full of xenon was disturbingly heavy. Balloons just aren't supposed to sink like that. I suppose I should fill a tub with xenon, and float some balloons full of air in it, but thats a lot of xenon...
Then, I had thought the xenon was a relatively large atom. Larger than nitrogen and oxygen at least. So I was expecting it to stay in the balloon for longer than it did. Turns out the balloon was dead within a day. It died much quicker than helium balloons I've had.
I suppose the reason is also obvious... But I haven't been in a physics class for over a decade, so right now its not. My favorite theory is that the partial pressure of the xenon in the balloon is 1 atmosphere, while the air outside the balloon has a xenon partial pressure of a hard vacuum. The Xenon was sucked out by osmosis.
That doesn't quite explain why a helium balloon lasts longer, since I wouldn't expect the partial pressure of helium in air to be that much higher than xenon's.
I suppose I should get a helium balloon and another xenon balloon, and properly compare them. But first, I must get another power supply...