Three curves of stability?

[occam]

I have been doing some analysis work on isotope data, and got some results which dont seem to appear in the literature.

I attach an extract from my findings

Any comments please?

[Klaynos]

They all look to be results of binding energy that can be found from the semi-empirical mass formula... :|

[swansont]

I don't see anything surprising in there, other than not really believing a graph having data associated with Z=285 and the vicinity. Any specific questions?

[occam]

They all look to be results of binding energy that can be found from the semi-empirical mass formula... :|

The only binding energy graphs are 6.5b; 6.6b; and 6.6e

 

I don't see anything surprising in there, other than not really believing a graph having data associated with Z=285 and the vicinity. Any specific questions?

Ah! Graph 6.1 should have read total nucleon A number. Thank you, I will amend

 

Any specific questions?

Some have queried the finding

• There is only one fully stable “Z” isotope for a given atomic Nucleon number “A” and there are only 194 of these.

 

Have you any problem with this?

[swansont]

Some have queried the finding

• There is only one fully stable “Z” isotope for a given atomic Nucleon number “A” and there are only 194 of these.

 

Have you any problem with this?

 

Since it's not true, then yes. I didn't realize this was being claimed.

[occam]

The main data came from the tables of Isotopes from Wikipedia

http://en.wikipedia.org/wiki/Isotopes_of_hydrogen etc

 

To this I have identified the decay mode, from

http://periodictable.com/Isotopes/001.3/index.p.full.dm.html etc.

 

The upload module would not let me attach the working spreadsheet, or an extract in doc format, so I hope you can decipher this. If not send me a message with a contact e-mail, and I will send you the original file.

Graham

[swansont]

You haven't made it clear what you're trying to prove.

 

As far as the "one stable Z for a given A" this is trivially falsified. Fe-58 and Ni-58 are stable. Se-80 and Kr-80 are stable. Sr-86 and Kr-86 are stable. And there are more.

[occam]

As far as the "one stable Z for a given A" this is trivially falsified. Fe-58 and Ni-58 are stable. Se-80 and Kr-80 are stable. Sr-86 and Kr-86 are stable. And there are more.

 

I agree these pairs are listed as stable in most general sources but as I wanted the decay modes I consulted periodictable.com published by Wolfram research, which I presume is a reputable source, and found additional data, for instance the page

http://periodictable.com/Isotopes/028.58/index.p.full.dm.html

shows 58Ni has a 2B+ decay of -118.68keV to 58 Fe

and

http://periodictable.com/Isotopes/034.80/index.p.full.dm.html

shows 80 Se is 2B- decay 132.56keV to 80Kr

and

http://periodictable.com/Isotopes/036.86/index.p.full.dm.html

86Kr is 2B- decay 1258.01keV to 86 Sr.

And so on.

Having crawled through all 3177 listed isotopes, I found that these additional decays accounted for all the duplicates in the A numbers, leaving just one Z number for each which is fully stable (according to Wolfram). In 14 cases between 1 and 208. there is no stable Z number.

Which is why I raised the question (in several forums). It appears that no one has noticed this before.

[swansont]

The decays are possible because of the energy difference — in any list, only one value can be smallest. But are these decays actually observed?

[occam]

But are these decays actually observed?

I think they must be. Although the isotope tables in Wikipedia show these as “stable” the remark is qualified by a very long half-life figure, I cannot imagine that these would be included without some evidence. However it looks like I’m going to have to do more research for supporting evidence.

[swansont]

The wikipedia entry on double-beta decay says otherwise

 

http://en.wikipedia.org/wiki/Double_beta_decay

 

In most cases, the double-beta decay is so rare as to be nearly impossible to observe against the background of other radiation.

[occam]

In most cases, the double-beta decay is so rare as to be nearly impossible to observe against the background of other radiation.[/i]

And of course you have answered your question. It may be rare, but for these isotopes the preobability of decay is greater than zero.

All I have done is eliminate these from the list so that only the isotopes with zero decay probability remain.(which is where I came in!).

[John Cuthber]

OK, how fast is proton decay? Anything slower than that might as well be stable.