The rarest element

[Drilon]

Which is the rarest chemical element. I heard that it is Francium but I'm not sure.

[EvoN1020v]

How about Element 118?

 

http://www.scienceforums.net/forum/showthread.php?t=24245

[jdurg]

How about Element 118?

 

http://www.scienceforums.net/forum/showthread.php?t=24245

 

Doesn't count. If you go by that criteria, then I'd say element 119 or element 120 because there is a chance that at one point in time one or two atoms of those elements were created but weren't detected. Therefore, they would be considered "the rarest".

 

In reality, any element that occurs, or can occur, due to natural processes on Earth are considered as possibilities for rarest. Francium currently holds that title since its half-life is so short that even if it were created in bulk you'd never have a large amount of it. Astatine, at least, has an 8-hour half-life so you could theoretically generate a large amount of it and refine it before it decays away. With francium, you just don't have enough time.

 

Some of the trans-uranic elements fall into the rare category as well since only a few trace samples of them have been found on earth due to natural radioactive processes. However, because of all the radioactive fallout caused by nuclear weapons testing and research you can never be sure if they were created by natural methods or because of man.

[EvoN1020v]

jdurg, did you read my Element 118 thread at all?

 

"[Element 118] is also one of the shortest-lived, decaying in less than a millisecond." (extracted from the Element 118 thread)

[jdurg]

jdurg, did you read my Element 118 thread at all?

 

"[Element 118] is also one of the shortest-lived, decaying in less than a millisecond." (extracted from the Element 118 thread)

 

Yes, and did you read my post at all????? The man-made elements DO NOT COUNT when you are talking about the "rarest" of elements. This is because in all actuality they DO NOT EXIST!!!!! They only exist because man has made one just to say that he has. It does not make it rare at all since if you really wanted one, all you would need to do is go and make some more. As a result, it is completely unlimited and as such it is not rare at all. When you get into a discussion about "rare elements" you can only include those that naturally occur on earth. Please read the entire thread before you go around stating things as facts.

[EvoN1020v]

Yes, and did you read my post at all????? The man-made elements DO NOT COUNT when you are talking about the "rarest" of elements. This is because in all actuality they DO NOT EXIST!!!!! They only exist because man has made one just to say that he has. It does not make it rare at all since if you really wanted one, all you would need to do is go and make some more. As a result, it is completely unlimited and as such it is not rare at all. When you get into a discussion about "rare elements" you can only include those that naturally occur on earth. Please read the entire thread before you go around stating things as facts.

 

Ah, understood. My apologies.

[Gilded]

I'd imagine the rarest stable gas in the atmosphere would be xenon but I wonder what's the rarest stable element in the Earth's crust? Iridium? Osmium?

 

Edit: Or now that I think of it, it certainly could be rhodium, at least if prices are anything to go by.

...

Turns out iridium is the rarest stable element in seawater, apparently.

[jdurg]

Ah, understood. My apologies.

 

No problem. Sorry for my little rant there. I always get quite edgy during Christmas for some reason.

[jdurg]

I'd imagine the rarest stable gas in the atmosphere would be xenon but I wonder what's the rarest stable element in the Earth's crust? Iridium? Osmium?

 

Edit: Or now that I think of it, it certainly could be rhodium, at least if prices are anything to go by.

...

Turns out iridium is the rarest stable element in seawater, apparently.

 

Iridium is the "rarest" of the stable elements on Earth, followed closely by osmium and rhodium.

[budullewraagh]

Actually, for the record, astatine is more rare than francium. The latter is present in quantities estimated at 340-550g at any given moment while the former is present in quantities of less than 1oz, estimated at closer to 25g. According to wikipedia, Asamov estimated that only about a trillion atoms of At are present on earth at any given time. This doesn't make a whole lot of sense considering the fact that 25g of At (assuming the atomic mass of At is approx 210) is approx 0.119 moles, which would be approx 7.16*10^22 molecules.

[Gilded]

The 25g of astatine is mentioned in the new Guinness World Records too (without any mention of its extreme unstability being the reason to its scarcity). I'd like to see them list some stable element records for a change though.

 

Anyhow, I'm happy to hear that iridium is the rarest stable one as I have a 5g pellet of it.

[jdurg]

The 25g of astatine is mentioned in the new Guinness World Records too (without any mention of its extreme unstability being the reason to its scarcity). I'd like to see them list some stable element records for a change though.

 

Anyhow, I'm happy to hear that iridium is the rarest stable one as I have a 5g pellet of it.

 

Yup. Iridium kind of proves that "rarity" doesn't exactly denote cost. Rhodium is multiple times more common than iridium, yet an ounce of Rh costs 10 times as much, if not more, than an ounce of Ir. (I have about 40 grams of Ir yet only 10 of Rh thanks to the insane price of Rh). Price of elements all comes down to a combination of rarity, and ease of extraction.