Francium

[SGOS]

I was reading last night, and in passing, the book mentioned what may be the rarest element on Earth, Francium.  It said there may be less than 20 atoms of Francium on Earth at any given time.  Now that disagrees with the following link, which says the amount of Francium on Earth is more like 30 grams, which is still rare, of course.  Also, the link calls it the second rarest element.

I assume the rarity is because of its instability.  It only lasts about 20 minutes during the process of radioactive decay, and then it's gone (or transmuted into something else).  Actually, it lasts longer.  20 minutes is it's half life.  But still...

I just thought this was interesting.

http://www.chemicool.com/elements/francium.html

[aitm]

Less than thirty grams of francium exists on Earth at any given time.

boy I really hate statements like these. How can we really know this? I mean we have access to only 1/1000(give or take anywhere from 0 to a billion) of the earths mass, how can we make such certain statements?

[Hakurei Reimu]

boy I really hate statements like these. How can we really know this? I mean we have access to only 1/1000(give or take anywhere from 0 to a billion) of the earths mass, how can we make such certain statements?

Briefly? Because our ability to estimate the earth's composition doesn't depend on the relative size of our sample to the population (statistics works even with finite samples of infinite populations). Good estimates on the Earth's composition merely depend on being able to get a good sample of the Earth's material. Once you have a good sample, you can estimate the amount of U²³⁵ in the Earth at present, and from that compute the abundance of each daughter element all the way down the decay chain.

As such, if the Earth's supply of francium isn't ~30 g, there is something very very wrong with our earth sciences.

[SGOS]

I had the same question, but never thought to articulate it.  I just wrote it off to those little scientist dudes who devise ingenious little ways to figure this stuff out.  Yeah, they get things wrong often enough, too.  Hell, it might turn out to be 33 grams.  Then we'd all be fucked for sure.  I'd probably go join a church, where such ultimate truths are timeless and recorded by unknown writers of antiquity (when they weren't too busy with their goat herds).

[Atheon]

I have a kilo of francium in my basement. Prove I don't!

[aitm]

Briefly? Because our ability to estimate the earth's composition doesn't depend on the relative size of our sample to the population (statistics works even with finite samples of infinite populations). Good estimates on the Earth's composition merely depend on being able to get a good sample of the Earth's material. Once you have a good sample, you can estimate the amount of U²³⁵ in the Earth at present, and from that compute the abundance of each daughter element all the way down the decay chain.

As such, if the Earth's supply of francium isn't ~30 g, there is something very very wrong with our earth sciences.

well sure, if you put it that way.....but what if they knew about the secret supply under mount doom in the black land of mordor? Huh? Then what Mr. Fancy pants? aint no goddamn samplin shit down there....so there!

[SGOS]

I have a kilo of francium in my basement. Prove I don't!

Well, you better hurry up and smoke it, or it will all disappear.

[stromboli]

Francium is like the Scientology of elements. You're not sure how much of it there is, it comes and goes, and it is really, really unstable.

[SGOS]

America needs more Francium, and neither the Republicans or Democrats are doing a damn thing about it.

[Atheon]

Why do we need more Francium when we have Americium!

[aitm]

Why do we need more Francium when we have Americium!

GOD BLESS AMERICIUM!! YA'LL LEAVE IF'N YOU DON'T LIKE IT!!

[stromboli]

FRANCIUM? 

[Atheon]

GOD BLESS AMERICIUM!! YA'LL LEAVE IF'N YOU DON'T LIKE IT!!

Some of us are fortunate enough to have grown up in a city with its own element.

Berkelium. It's a city in Californium, on the west coast of Americium.

[stromboli]

Utahium? Salt Lake Cityium? Hmmm........