Talk:Isotopes of polonium

²¹⁰Po toxicity

One microgram is not enough to kill anyone. I estimate the committed dose to a 91 kg man for a microgram of ²¹⁰Po would be around 0.08 Sv. That would not be enough to kill anybody. However a milligram would work just fine. It would deposit a committed 4 Gy dose equivalent to 82 Sv. The lethal quantity of one microgram should be changed in the text.
This was calculated using the half-life of ²¹⁰Po, the biological half-life of 50 days, and the absorption into the body of about 75% of that ingested.Pionade (talk) 16:00, 7 November 2014 (UTC)

The RSC article on Po210 indicates a fatal dose of a microgram, not a milligram. Since the dose has now been altered to a milligram in the article, should not the relative toxicity compared to cyanide be edited down to 250, not 250000? Chrisj1948 (talk) 17:09, 31 July 2015 (UTC)

Po-210 Specific Activity

Po-210 has a half life 4223 times shorter than Ra-226 (365.25/138.376)*1600. So that a certain number of atoms say 2.868E+18 (1mg) would produce the same decay rate (166.3GBq) as 1.211E+22 (4.546g) Ra-226 atoms. This checks C. R. Hammond's value given in the Handbook of Chemistry and Physics (as 5g). Darian2 (talk) 23:06, 2 October 2012 (UTC)

Z column

The Z column in the table is redundant. By definition, the polonium nucleus contains 84 protons. Axl ¤ [Talk] 19:18, 31 July 2014 (UTC)

Yes, but what's wrong with a little reminder? Double sharp (talk) 06:14, 25 September 2015 (UTC)

External links modified

Hello fellow Wikipedians,

I have just added archive links to one external link on Isotopes of polonium. Please take a moment to review my edit. If necessary, add {{cbignore}} after the link to keep me from modifying it. Alternatively, you can add {{nobots|deny=InternetArchiveBot}} to keep me off the page altogether. I made the following changes:

• Added archive http://web.archive.org/web/20150224043744/http://atom.kaeri.re.kr/cgi-bin/decay?Po-210%20A to http://atom.kaeri.re.kr/cgi-bin/decay?Po-210%20A

When you have finished reviewing my changes, please set the checked parameter below to true or failed to let others know (documentation at {{Sourcecheck}}).

This message was posted before February 2018. After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template {{source check}} (last update: 5 June 2024).

• If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
• If you found an error with any archives or the URLs themselves, you can fix them with this tool.

Cheers.—^{cyberbot II}_{Talk to my owner:Online} 05:58, 21 March 2016 (UTC)

Magic numbers

The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

---

If Po210 has a magic number of neutrons and Po209 doesn't, then why is Po209 more stable than Po210? 32ieww (talk) 00:18, 19 February 2017 (UTC)

@32ieww: Magic numbers don't tell the whole story. Tin-100 is very unstable despite being doubly magic.--Jasper Deng (talk) 02:23, 1 March 2017 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

This is actually an interesting question, since ²¹⁰Po, unlike ¹⁰⁰Sn, falls exactly on the beta-stability line. I suspect this may be due to the loose binding of the valence protons in ²¹⁰Po; the nucleons forming the alpha particle are also already spin-paired in the decay of ²¹⁰Po to ²⁰⁶Pb, unlike that of ²⁰⁹Bi to ²⁰⁵Tl, and because this is an even-even decay the decay is not forbidden. Double sharp (talk) 11:31, 21 May 2017 (UTC)

External links modified

Hello fellow Wikipedians,

I have just modified 2 external links on Isotopes of polonium. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

• Corrected formatting/usage for http://atom.kaeri.re.kr/cgi-bin/decay?Po-210+A
• Added archive https://web.archive.org/web/20080923135135/http://www.nndc.bnl.gov/amdc/nubase/Nubase2003.pdf to http://www.nndc.bnl.gov/amdc/nubase/Nubase2003.pdf

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

This message was posted before February 2018. After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template {{source check}} (last update: 5 June 2024).

• If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
• If you found an error with any archives or the URLs themselves, you can fix them with this tool.

Cheers.—InternetArchiveBot (Report bug) 14:18, 15 April 2017 (UTC)

How to edit the footnotes to the table?

For example, the line "Bold italics symbol as daughter – Daughter product is nearly stable." cannot be edited by me because I cannot see it when I click on any of the edit links on the article page. Polar Apposite (talk) 17:18, 15 August 2023 (UTC)

The phrase "nearly stable" seems unclear.

In "Bold italics symbol as daughter – Daughter product is nearly stable.", how about substituting "has an extremely long half-life." or "is for all practical purposes stable" for "is nearly stable"? It's not clear what nearly stable means. It could mean, to some readers, that it has a short half-life due to an unlikely set of circumstances. Polar Apposite (talk) 17:24, 15 August 2023 (UTC)

How to edit the small table title?

The small table with the title "Isotopes of polonium (84Po)" is actually a table of the three important isotopes of polonium, and so I'd like to edit the title to say something to that effect, but I can't see how to that. Also, would that be a good idea? Polar Apposite (talk) 17:27, 15 August 2023 (UTC)

Alpha decay energies of isotopes of polonium

Isotopes	Alpha decay energy (MeV)	Note
186Po	8.50
187Po	7.97
188Po	8.08
189Po	7.69
190Po	7.69
191Po	7.49
192Po	7.32
193Po	7.12
194Po	6.99
195Po	6.70
196Po	6.66
197Po	6.38
198Po	6.31
199Po	6.07
200Po	5.98
201Po	5.80
202Po	5.70
203Po	5.50
204Po	5.48
205Po	5.32
206Po	5.33
207Po	5.22
208Po	5.22
209Po	4.98
210Po	5.41	Beta-stable with 126 neutrons
211Po	7.59	Beta-stable with 127 neutrons
212Po	8.95	Beta-stable with 128 neutrons
213Po	8.54	Beta-stable with 129 neutrons
214Po	7.83	Beta-stable with 130 neutrons
215Po	7.53
216Po	6.91	Beta-stable with 132 neutrons
217Po	6.66
218Po	6.11
219Po	5.91
220Po	5.37
221Po	5.11
222Po	4.61

Continutation according to this table:

Isotopes	Alpha decay energy (MeV)
173Po	11.12
174Po	10.78
175Po	10.26
176Po	10.21
177Po	10.22
178Po	9.87
179Po	9.47
180Po	9.34
181Po	9.17
182Po	8.87
183Po	8.63
184Po	8.55
185Po	8.39
186Po	8.29
...	...
222Po	3.42
223Po	2.94
224Po	2.68
225Po	2.50
226Po	2.23
227Po	2.01
228Po	1.82
229Po	1.70
230Po	1.46
231Po	1.23
232Po	1.12
233Po	1.02
234Po	0.82
235Po	0.57
236Po	0.44
237Po	0.20
238Po	-0.06
239Po	-0.35
240Po	-0.41
241Po	-0.36
242Po	-0.67
243Po	-0.93
244Po	-1.03

129.104.241.218 (talk) 06:17, 15 March 2024 (UTC)

Possible double beta minus decay of ²¹⁶Po

²¹⁶Po is potentially capable of double beta minus decay, although the estimated half-life should be very long. 129.104.241.214 (talk) 11:35, 28 November 2023 (UTC)

Do you have a source for this statement? Dirac66 (talk) 22:28, 28 November 2023 (UTC)

Nothing special. It's just a comparison of the mass of the two nuclides. 129.104.241.242 (talk) 04:12, 29 November 2023 (UTC)

Wikipedia would only include that sort of prediction if it were published in the scientific literature. Otherwise we would be doing original research without reliable sources, which is not allowed. See WP:NOR. Dirac66 (talk) 02:06, 30 November 2023 (UTC)

OK, thanks for your reply. 129.104.241.214 (talk) 02:39, 30 November 2023 (UTC)

It is listed in this source. Double sharp (talk) 08:39, 13 December 2023 (UTC)

@Double sharp. Thank you for this source. I have now added this information as a comment below the List of isotopes. We could insert the comment instead in the line for ²¹⁶Po, but I was not able to figure out how to do that. Dirac66 (talk) 22:38, 24 December 2023 (UTC)

It seems that we can't insert a reference into a comment line. 129.104.241.214 (talk) 21:29, 27 December 2023 (UTC)

I've directly added this to the table because the double beta minus decay of ²¹⁶Po is already mentioned in NUBASE2020. 129.104.241.214 (talk) 14:35, 28 December 2023 (UTC)

²¹²Po as a naturally existing nuclide

²¹²Po has the shortest half-life (294.4 ns) and highest decay energy (8.95412 MeV) among the decay products of primordial ²³²Th, ²³⁵U, ²³⁸U. ²¹⁴Rn has larger decay energy (9.2084 MeV), but it does not exist in nature.

²¹²Po is followed by ²¹⁵At (100 μs), ²¹⁴Po (164.3 μs), ²¹⁵Po (1.781 ms), ²¹⁸Rn (35 ms), ²¹⁶Po (145 ms), ²¹¹Po (511 ms) among the decay products.

²¹²Po is very similar to ⁸Be as α + doubly-magic nuclei that have the lowest energies (so they look stable a priori) and yet are the least stable among their isobars (⁸He and ²¹²Pb are more stable by respectively 15 and 11 orders of magnitude). 129.104.241.242 (talk) 10:39, 4 December 2023 (UTC)

I now have a strong urge to salute Otto Hahn for identifying ²¹²Po as far back as 1906. O_O Double sharp (talk) 13:54, 28 December 2023 (UTC)

Agreed :) 129.104.241.214 (talk) 14:36, 28 December 2023 (UTC)

Why would NUBASE not list the 8⁺ state of ²¹²Po as an isomer?

Its half-life is 14.6 ns, so it qualifies to be an isomer. 129.104.241.242 (talk) 03:05, 3 May 2024 (UTC)

According to page 030001-2 of NUBASE2020, only isomers with half-life >100 ns will be listed. Nucleus hydro elemon (talk) 04:51, 3 May 2024 (UTC)

Ah, thanks! 129.104.241.242 (talk) 12:58, 3 May 2024 (UTC)

A convention not very fair for ²¹²Po: the g.s. half-life is only 294.4 ns, so 14.6 ns is not so short for deserving its own place in the isotope table. In fact, considering the alpha intensity of 3%, this isomer has even longer alpha half-life than the ground state :) 2A04:CEC0:10F4:BE6A:84C0:A2B0:36F4:AFE6 (talk) 17:08, 7 May 2024 (UTC)

Unfortunately, if we add this isomer of ²¹²Po, we also have to add a 89.3 ns state of ¹⁹F, a 21.8 ns state of ⁹⁸Mo, a 35 ns state of ¹⁴⁵Pm, a 35 ns state and a 78 ns one of ¹⁵¹Sm, a 25.6 ns state of ¹⁶¹Dy, a 18.7 ns state of ²¹²At, many states of ²¹²Rn, and a 42 ns state of ²⁴³Cm. 14.52.231.91 (talk) 00:17, 16 August 2024 (UTC)

Double alpha decay of ²¹²Po

Page 7 of this article mentions 7.3×10¹⁰ years as half-life of symmetric double alpha decay of ²¹²Po. 14.52.231.91 (talk) 01:39, 16 August 2024 (UTC)

These are theoretical predictions for a decay mode which has never been observed in any nucleus. –LaundryPizza03 (dc̄) 02:26, 28 August 2024 (UTC)

Of course, sorry if I meant the slightest indication of the contrary. 14.52.231.91 (talk) 09:05, 28 August 2024 (UTC)

Incorrect Decay Modes

The decay modes show a few instances of β+ (combined electron capture positron emission) with Po-206, Po-209, but NuDat3 does not contain datasets showing e+ positron emission, only electron capture upon spot checks. See NuDat3 Decay Radiation for Po-206, for instance. AndrewLakes (talk) 18:36, 30 October 2024 (UTC)

Explanation of 8.785 MeV-alpha particles

The Q-value of ²¹²Po is 8.95412 MeV, but I always heard that ²¹²Po releases 8.785-MeV α particles. There is a conversion between this two values.

Consider the decay equation A → B + C. After decay both B and C have some momentum p, in opposite directions, so we have

$E_{B}'^{2}={\sqrt {p^{2}c^{2}+E_{B}^{2}}},\quad E_{C}'^{2}={\sqrt {p^{2}c^{2}+E_{C}^{2}}},$

where E_B, E_C are the rest energies and E_B', E_C' are actual energies after decay. Energy conservation gives $E'_{B}+E'_{C}=E_{A}$, so

$E'_{C}+{\sqrt {E_{C}'^{2}+E_{B}^{2}-E_{C}^{2}}}=E_{A},$

which means that $E'_{C}={\dfrac {E_{A}^{2}-E_{B}^{2}+E_{C}^{2}}{2E_{A}}}$, so the kinetic energy of C is $E_{kC}=E'_{C}-E_{C}={\dfrac {(E_{A}-E_{C})^{2}-E_{B}^{2}}{2E_{A}}}$. Or in terms of Q-value, $E_{kC}={\dfrac {E_{A}+E_{B}-E_{C}}{2E_{A}}}Q$, so ${\dfrac {E_{kC}}{E_{kB}}}={\dfrac {E_{A}+E_{B}-E_{C}}{E_{A}+E_{C}-E_{B}}}$. This is intuitive enough: for alpha decay of a nucleus with mass number A, we have $E_{k\alpha }\approx {\dfrac {A-4}{A}}Q$.

For decay of ²¹²Po, the value is ${\dfrac {(211.9888680-4.00260325413)^{2}-207.9766520^{2}}{2\times 211.9888680}}=0.009431028\,u$ which is equal to 8.785 MeV. 129.104.241.224 (talk) 06:04, 2 December 2024 (UTC)

²⁰⁸Po

²⁰⁸Po should have been beta-stable given its position relative to the beta-stability line. But it is not, even far from being so: its beta-decay energy is extremely high as 1400.5 keV. Remark that ²¹⁶Ra, having already fell off the beta-stability line, has only a beta-decay energy of 320 keV. I would say that ⁹⁰Sr and ⁸⁸Zr should also have been beta-stable even more, and they are in fact both closer to being so.

So the energy of ²⁰⁸Po is exceptionally high; it should have had an energy 1.5 MeV lower (if so, the alpha half-life of ²¹²Rn would be reduced to around 10^-4 s). 129.104.241.222 (talk) 16:34, 18 December 2024 (UTC)