First Superheavy Element Found In Nature

KentuckyFC writes "The first naturally occurring superheavy element has been found. An international team of scientists found several nuclei of unbibium in a sample of the naturally occurring heavy metal thorium. Unbibium has an atomic number of 122 and an atomic weight of 292. In general, very heavy elements tend to be unstable but scientists have long predicted that even heavier nuclei would be stable. The group that found unbibium in thorium say it has a half life in excess of 100 million years and an abundance of about 10^(-12) relative to thorium, which itself is about as abundant as lead." I'd also like it known that my spell checker did not know 'unbibium' before today, but it is now one word closer to encompassing all human knowledge.

Comments

Very doubtful

[Anonymous Coward]

I'm a professor of isotope geochemistry.

After reading their paper, it's clear they haven't proven their case. There are *so* many possible explanations for the handful of counts they observed that this result should be ignored. Let me give a few:

- Molecular ions. They say there are no known molecular ions at this mass, I say BS. There are lots of observed molecular ions out there whose exact atomic makeup we haven't figured out. The worst is the interference on 87Sr that screws up lots of icpms age dating work and is not 87Kr (or we could correct for it). But there are others.

- Hydrocarbons: They say there are no hydrocarbons in the blank -- have they ever thought of hydrocarbons that are only ionized when lots of other things (ie a sample) is being ionized? No. They exist though, and are difficult to rule out. They didn't try very hard on this one. Try aspirating a solution of something else (U maybe, or Pb) and see what they get on 292. I'll bet there are counts, and they're not superheavies.

Another reason to be skeptical is that their Th solution is chemically purified. How are they going to do that without getting rid of the superheavy, which is after all not Th, and will be removed by any chemical process.

This is highly dubious work.

How are these elements formed?

[Jugalator]

Let's say it has a half-life of around 100 million years then. But how are they formed? I thought only heavy naturally occuring elements were formed in high energy situations like supernovae, but this is would be a relatively speaking short timeframe.

So how are minerals with a "short" half-life formed on Earth? Wouldn't it require a quite immense energy to fuse these atoms? I suppose the Earth has to have the energies necessary, but... What's this talk about supernovae being required to fuse atoms heavier than iron (unlike typical star fusion that I believe can go as far as this) all about in that case?

Valence electrons

[LotsOfPhil]

The last electrons to go in are 5g electrons. So, these nuclei have the only non-excited 5g electrons. It adds another step to the periodic table. This is super neat.
Extra steps.

Neither new nor certain

[Ancient_Hacker]

Long ago there was found considerable evidence for heavy elements. If you peer at any chunk of mica you can find long dark tracks, longer and darker than are caused by any known type of radioactive decay. The trick is finding incontrovertible proof of these atoms *before* they decay. If they have short half lives (short as in under ten million years or so), it's going to be hard to find their needleness in the haystack.

Re:names

[neokushan]

Interestingly enough, google didn't recognise the word "unbibium", the name given to a recently discovered element in the periodic table (According to wikipedia) and instead asked if I meant unbiunium, the temporary name given to an as-yet undiscovered element of the periodic table.

Re: one technique for finding them.

[misterjava66]

One of the places considerred for finding 122,124,& 126 is in the X-ray adsobtion lines in super-novas. Then look at how those lines change over time, and half-lives can be measured.

btw we can be assured that it is VERY unlikely that 126 is stable since we can't find any of it. We can be quite sure that anything with a half-life of >1Byr would be findable in some amount in all the searching that has been done.

Also, although 126 is 'perfect' in terms of protons, it is far from perfect in nuetrons, that is why 122 and 124 are more often sought, a little low on protons and a little high on the nuetrons might still find a some-what stable nucleaus.

It is VERY exicting news though. Element 122 with such a massive nucleaus will have a number of very special properties.

:-)

Why isn't there more of it?

[Starker_Kull]

If this result holds up, all sorts of interesting questions come up. For instance:

They claim it's half-life is about 10e8 years. Since our solar system is very roughly 1e10 years old, that's about 100 half-lives, or a decrease by a factor of 2^100 or about 1e30. Since its atomic weight is 292, that suggests that an original sample of about 292e7 grams should have decayed to 1e7 moles * 6e23 at/mol / 1e30 = 6 atoms left. In other words, an original chunk of this stuff of mass 2,920,000 kilos would have decayed to 6 atoms. But when you condsider how much mass of all sorts of elements exist on the earth, and take into account chemical concentration, one would think more of this stuff would be around.... maybe. Does anyone know about the frequency of discovery of naturally radioactive isotopes with a similar half-life that are not part of the decay path of other longer lived radioactive isotopes? In other words, is it reasonable to expect to find significant quantities of something with a half-life of around 1e8 years that isn't being formed from other decay products any more?

Also, if the reason it is so rare is because so little was formed, perhaps that indicates it is extremely hard, even in a supernova, to create this element? What does that suggest about our ability to artificially synthesise this element?

Very interestng....

Re:names

[jd]

Well, if there are enough nuclei, then expect both, the ratio of the two being about equal to the probability of them being there. Even if the heavier element does not exist in the sample, there may be evidence of it having been there. This assumes the decay chain can be predicted. If the decay products (daughter isotopes) in the chain are present and in the expected ratios, then you can deduce that the prior isotope in the sequence must have been present at one point. How do you tell what is a decay product and what naturally occurs? You'd need a radiochemist to explain it better than I can, but one quick-n-dirty answer is that you can start by seeing if there's something that would be there if such-and-such a scenario is true but isn't. Say you're expecting a stable decay product and it's just not there. Well, it hasn't decayed - it's stable - and it didn't just walk off, so this would be strongly suggestive (in that case) that the parent radioisotope was never present.

(Actual radiochemisty tends to be rather more complex than this simplistic description. I only had to write an expert system and inference engine for isotope identification, I didn't need to know all of the nuances of the field, such as anti-aliasing AMS data or worrying about characteristic distributions of gamma ray energies. They told me the peak energies and the known isotopes present for a given sample, the software then tried different scenarios and listed those which fit the available data along with the corresponding probability.)