Talk:Radioactive decay

definition of radioactive decay

Hi i was just wondering why it isnt explicitly pointed out that for an atom to be considered radioactivelly decaying it would have to be emitting ionizing radiation. Without ionizing explicitly being stated, emittance of infrared radiation could also be considered radioactive decay, no? "Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation" it is not clear if in this sentence "unstable" is ment as a vague term, or in the physics sense of the atom containing more energy than its ground state. If the latter, once again, the absorption of lets say yellow light which results in for example the emittance of infrared radiation could be considered radioactive decay. I am in no way trying to be rude, i just ran into this problem while trying to understand the exact definition of radioactive decay. If i was wrong anywhere in my comment please do point it out.

Greetings,

Sander — Preceding unsigned comment added by Sander721 (talk • contribs) 23:05, 5 February 2021 (UTC)

Thanks for the suggestion. I suspect that "ionizing radiation" was not mentioned because it is a somewhat old-fashioned term not much used now. However I found it mentioned in an introductory chemistry text and attributed to the Curies, so I have now included it in the History section, as well as a link to the article Ionizing radiation which explains it in detail. Dirac66 (talk) 20:06, 18 February 2021 (UTC)

If "ionizing radiation" is old fashioned, then perhaps you could say what modern terminology is used to denote radiation that is able to ionize chemical substances, as distinct from radiation that cannot do so. 2600:4041:DF:9600:4503:4891:B9B:EE5E (talk) 12:12, 14 September 2023 (UTC)

The modern terminology used to describe each radioactive decay process is to identify the exact particles emitted in each decay process as α particles, β particles, γ rays etc. However I will admit that the term "ionizing radiation" is still accurate as a general term, and is still used in many other contexts. See the article Ionizing radiation for more detail. Dirac66 (talk) 15:17, 14 September 2023 (UTC)

On the decay modes in the table

Hi everyone. I just wanted to ask about the table displaying the radioactive decay modes, since I'm currently working on the "Isotopes of" pages. While I was editing some of the pages, I found that NUBASE2020 lists a couple of decay modes that are not mentioned in the table. Furthermore, there is some notation that I'm not really sure how to go about adding it to the decay modes:

(note: "α" is used in the paper (PDF page 19) as an example)

"α ? means that the α-decay mode is energetically allowed, but not experimentally observed

α=? means that the α-decay is observed, but its intensity is not experimentally known"

Thanks! :)

– MeasureWell (talk) 01:44, 2 February 2022 (UTC)

I would generally favour listing in an encyclopedia only what has been observed. So modes marked "α ? by NUBASE I would omit entirely, and modes marked α=? by NUBASE I would list as α-emitters but not mention the intensity. Dirac66 (talk) 19:55, 2 March 2022 (UTC)

Question merged into § List of decay modes, 2020, foer example on how to note these in the ~118 Big Isotopes Tables. -DePiep (talk) 10:18, 3 March 2022 (UTC)

science

what happens in real life connections to these elements? 2A02:6D40:3405:7201:C4D:F8BE:4256:6032 (talk) 17:07, 25 February 2022 (UTC)

Some radioactive isotopes (not all) have practical applications, which are often mentioned in the articles on isotopes of each element. Dirac66 (talk) 19:59, 2 March 2022 (UTC)

List of decay modes, 2020

MeasureWell asked me to update the table § List of decay modes, into NUBASE 2020 status.

Trying to get this right, especially to cover the ~118 Big Tables § List of isotopes. My outline:

1. Template-table {{Decay modes}} to be updated (live in Radioactive decay § List of decay modes),

2. Defining source is {{NUBASE2020}}, [sole source?] see ...

3. ... see table "Decay modes and intensities" on e-page 19–20 / 181 (page 030001-18, -19). This table has 2527 entries all-in-all (α ... SI; also 2n, 2p).

4. Table header notes the "?" notation: α ?, α=?. How should this appear in the table?

5. Also in this table, in top, is local uncertainty notation, to be read as "a=25.9 % ± 2.3 %" (example): editors are supposed to werote the result not the NUBASE notation (not the meaningful-space-notation)

6. Also: aim is to make these correctly & easily available in our Big Isotopes tables, ~118, both in-table (for editor to input; can we easify?) and as optional standard footnote by {{Isotopes table}} header (expanding the current list of |notes=CD, EC, IT, SF, n, p, see example Isotopes of helium § List of isotopes. Both as editors input, and in default-text footnotes.

-DePiep (talk) 10:15, 3 March 2022 (UTC)

7. 2016, same table: NUBASE 2016. diff: minor. Appears that enwiki deviated mostly from that table. -DePiep (talk) 14:02, 4 March 2022 (UTC)

OK, below is the new 2020 table. The complete 2020 list is in there, with change notes. Also, some disappeared/not-found 2016-entries are listed. From here, I need physics input. Could someone, for example, start filling the empty/new cells in {{Decay modes/2020}}? DePiep (talk) 13:41, 3 March 2022 (UTC)

Working

The table now has all curent and previous DMs. The physics, wikilinks, text need a check. Also, some merge or additions could be needed.

sort: order in 2020 NUBASE Table; also groups related DMs. Also ID.

Code: simplified input, eg for templates in Isotope infoboxes (|dm=b+2n; future use)

2020 change: change re 2016 table, or change re enwiki usage so far. (many MDFs are not used)

Mode: some merges with 2016? Do we use the rare and new ones?

Name: descriptive name + wikilink (many missing, some trivial & not helpful)

Action: dsscription. To check & complete

AZ: number changes

note: -

Comments, proposals?-DePiep (talk) 20:04, 4 March 2022 (UTC)

@DePiep: Couple of days late, but from what I can tell, it looks quite good so far - great job! :D I just have a couple of comments and suggestions.

(DISCLAIMER: I am not an expert in nuclear physics. If I've gotten anything wrong, please feel free to tell me :D)

1. I've just checked the original NUBASE2020 paper, and it states that "IS" is their abbreviation for "isotopic abundance". Since we already have that in Template:Isotopes_table (i.e. the "Natural abundance" column), in my opinion we could do away with it entirely.
2. For your question regarding whether 260 (heavy cluster emission) and 262 (cluster decay) are the same, I've just checked the nuclides listed to undergo cluster decay on the Wikipedia page on the same subject with NUBASE2020, and so far, all of the nuclides listed that are correct (i.e. almost all of them) correspond with what NUBASE2020 refers to as "heavy cluster decay". In other words: as far as I can tell, heavy cluster emission and cluster decay are the same thing.
3. This might be just me, but, assuming that I've read the new table correctly, I don't 100% get why spontaneous fission has been removed from the new table - it pops up in both NUBASE2016 and NUBASE2020. There are a couple of the heavier nuclides from the table on the Cluster decay page that are also listed in NUBASE2020 with SF as a decay mode (you'll find them everywhere from nuclides with mass numbers of 221 onwards).
4. As you've mentioned before in this talk page, NUBASE2020 (and NUBASE2016 as well, for that matter) both clarify what they refer to as "β⁺ decay" is equal to "β⁺ = ε + e⁺", where "ε" is electron capture and "e⁺" is positron emission. Hopefully this may help clear up some confusion?

Great job anyways, and thanks for taking my proposal seriously. :D

Cheers,

—MeasureWell (talk) 03:46, 9 March 2022 (UTC)

Thanks MeasureWell; works into a solution: 1. new table in Decay mode article, and 2. in all decay listings & tables. -DePiep (talk) 07:18, 21 March 2022 (UTC)

5. New issue: Isotopes of beryllium mentions γ decay for ⁷Be (in the infobox only, not in the Big Table?!). What to do with this one? Gamma is not listed in NUBASE at all. -DePiep (talk) 07:18, 21 March 2022 (UTC)

@DePiep: Right, I'm onto this. I checked NUBASE2020 and it gives only electron capture for ⁷
Be
; I then checked NuDat (which is maintained by IAEA) and got to the page on ⁷
Be
, which corroborates NUBASE2020. However, it also does give some values under the heading "Gamma and X-ray radiation". I checked Electron capture and it does mention that a gamma ray is also emitted during electron capture. I also managed to find this helpful diagram, and, from what I can tell, a gamma ray is indeed emitted when ⁷
Be
decays via electron capture (ε).

While we're at it, I got a couple of other small things we could do to fix up the table:

• Since "IS" in NUBASE2020 is used as a shortened way of saying "isotopic abundance" (which is, quite clearly, NOT a decay mode), I think we could remove it from the table entirely.
• "Spontaneous fission" is also given in NUBASE2020 as a decay mode, so I think that we could keep that in the main table as well and move it with the other decay modes.
• Assuming that we do decide to go ahead and use the NUBASE notation for decay modes, I think, if possible, it would also be valuable to provide other notation methods that are frequently encountered in the literature, for obvious reasons. Not everyone may be familiar with the NUBASE notation, and we don't want to give the incorrect impression that the NUBASE notation is the only "correct" notation for decay modes.

Also, I've put this up on Wikipedia talk:WikiProject Physics to try to get a bit of help over here and (hopefully) speed up the process. In the meantime, I think this gives me the green light to get rid of the "gamma decay" row for ⁷
Be
. Let me know if you've got any other questions, and please keep me in touch with any progress on the isotope tables as well! :) — MeasureWell (talk) 08:11, 21 March 2022 (UTC)

@DePiep: I have now removed the row in question from the Isotopes of beryllium infobox. Hopefully this should avert any more confusion regarding this in the future. — MeasureWell (talk) 08:19, 21 March 2022 (UTC)

Will work on this, but not these days (RL). Longer term: will check all input in tables (like {{these}}) for codes used. -DePiep (talk) 08:28, 21 March 2022 (UTC)

6. About εε (row 910): not in NUBASE, used & listed in enwiki (today). See table for usage (articles having "εε" linked to Double electron capture. -DePiep (talk) 08:28, 21 March 2022 (UTC)

Hi, folks! I'm reasonably conversant with radioactive decay, but there's so much back-and-forth here, I'm a little fuzzy on what the unresolved issues are. What can I help with? PianoDan (talk) 23:15, 21 March 2022 (UTC)

@PianoDan: Sorry for the late reply! Thanks for offering to help – the main issues here (most important issues at the top), as far I as can tell, are these:

• Check that the AZ values for β⁺ and β⁺-delayed decay modes from NUBASE2020 are correct
• Check that the decay modes given are consistent with NUBASE2020
• Check that the descriptions for each decay mode are correct

Also, I think that after it would also be a good idea to add a footnote to the β⁺ and e⁺ rows to indicate differences in notation, because I'm quite sure that most readers will be unfamiliar with the NUBASE2020 notation. Once again, thanks for the help!

— MeasureWell (talk) 23:12, 4 April 2022 (UTC)

* Check that the AZ values for β+ and β+-delayed decay modes from NUBASE2020 are correct

- As far as I can tell, these are accurate. I agree with the assessment that "Heavy Cluster Emission" and "Cluster Decay" are the same thing, and that ²⁴Ne was simply a particular example chosen for the table. I'll add an additional line to the table as a suggestion for what a combined line could look like. PianoDan (talk) 16:50, 7 April 2022 (UTC)

On second thought, line 262 seems mostly fine, although I'm confused by the AZ numbers. Shouldn't that last value simply be (A-A₁, Z-Z₁)? If you add A₁, Z₁ back in, you're just back where you started. PianoDan (talk) 16:56, 7 April 2022 (UTC)

Replying to myself: Oh, I see - the intent is to show both daughter products. In that case, I think they should be separated by a comma, a semicolon, or an ampersand - anything but a plus sign, which could confuse the issue. PianoDan (talk) 17:34, 7 April 2022 (UTC)

* Check that the decay modes given are consistent with NUBASE2020

* Check that the descriptions for each decay mode are correct

Comments:

- What is the purpose of the "code" column, as independent from the "Mode" column? Why do we have both?

- I agree that 60 and 62 are the same thing. ε is the more current usage, per NUBASE2020. I don't think the note is necessary, since the name is right there.

- If we want to be consistent with NUBASE, 2p and 2n should be "2-proton emission" and "2-neutron emission", not "double neutron emission" and "double neutron emission." On the other hand, NUBASE DOES use "double $\beta ^{+}$ decay" and "double $\beta ^{-}$ decay" The inconsistency is a little weird, but I think we should mirror it.

- In that vein, the names for rows 80 to 110 should use the β symbol, rather than the word "beta" for consistency with both NUBASE and the other rows in the table.

- Beta Decay general observation:

In NUBASE, β+ decay is used to indicate that the nucleus can decay by EITHER electron capture (ε) or positron emission (e+), and the rate of β+ decay is the combination of the two. (β+ = ε + e+) Do we wish to indicate that in some way?

- Rows 3xx ARE in NUBASE 2020, so should be included. To be clear, the difference between cluster decay and spontaneous fission is that in cluster emission, the SAME smaller nucleus is emitted each time, where SF can produce a range of daughter products. We should probably mention that explicitly in the SF line.

PianoDan (talk) 17:32, 7 April 2022 (UTC) PianoDan (talk) 17:32, 7 April 2022 (UTC)

@PianoDan:

What is the purpose of the "code" column, as independent from the "Mode" column? Why do we have both?

• I think you're better off asking DePiep that question, since they are the original creator of this template. Unfortunately, they're currently busy IRL, so it might take a while for a response.

In NUBASE, β+ decay is used to indicate that the nucleus can decay by EITHER electron capture (ε) or positron emission (e+), and the rate of β+ decay is the combination of the two. (β+ = ε + e+) Do we wish to indicate that in some way?

• Yeah, sure, go ahead. Since other websites generally use the ENSDF notation (i.e. ε = electron capture, β+ = positron emission) to indicate these decay modes, I think that it would definitely help to make it clearer to readers who might be unfamiliar with the notation used in NUBASE.

Rows 3xx ARE in NUBASE 2020, so should be included. To be clear, the difference between cluster decay and spontaneous fission is that in cluster emission, the SAME smaller nucleus is emitted each time, where SF can produce a range of daughter products. We should probably mention that explicitly in the SF line.

• Yup, good idea – also, thanks for the clarification: I initially got confused between the two as well :).

Tell you what: I'll move the rows over and change the names of 2p and 2n to those in NUBASE2020, while you can add the descriptions and indications (you're an expert in this, I'm not). Thanks for the quick response! — MeasureWell (talk) 01:25, 8 April 2022 (UTC)

@PianoDan: on the code column: is not for publication, but a preparation for usage in templates (like {{Infobox isotope}}), so that input is keyboard-easy and formal presentation is standardised. (Also helped me to find same/different forms in the decay modes). -DePiep (talk) 04:47, 8 April 2022 (UTC)

OK, I've updated all the descriptions and names to match NUBASE as well as the best of my understanding of how they all work. Given that beta+ decay is a compound rate in NUBASE, I'll let y'all figure out exactly what should be going on with redirects in that row. I also moved "Heavy Cluster Decay" to the bottom and cleared the note for electron capture. Let me know if there's anything else you need! PianoDan (talk) 16:45, 8 April 2022 (UTC)

Looks great! We can put it live (in {{Decay modes}} → appears in Radioactive decay § List of decay modes). No table subheaders any more like "Decays with emission of nucleons"? I can make a hardcode copy of the main columns if that helps. -DePiep (talk) 17:22, 8 April 2022 (UTC)

See Template:Decay_modes/testcases#hardcode_to_publish, a table more fit for publication. Anything else I can do to help? -DePiep (talk) 17:41, 8 April 2022 (UTC)

@PianoDan: I've just noticed that for some strange reason, isomeric transition (IT, which is given in NUBASE2020) is not listed on the table, and the decay name for β⁻SF is missing. I'll quickly go add the name for β⁻SF – is it possible to add IT to the table as a decay mode? Thanks for the help! — MeasureWell (talk) 09:16, 15 April 2022 (UTC)

On it. I'm adding it to the table linked just below, I hope that's the right place. PianoDan (talk) 14:42, 15 April 2022 (UTC)

@DePiep - I seem to have broken something in the code. PianoDan (talk) 14:50, 15 April 2022 (UTC)

@PianoDan and DePiep: I'm over a month late to this issue, but I've just gone ahead and added "IT" to the encoding for Template:Decay modes/2020, and from my end, it looks like the encoding problem has been fixed. I've also moved some of the encodings for decay modes that are not intended to be in the final table to the "2016" section.

Cheers — MeasureWell (talk) 23:50, 22 May 2022 (UTC)

I think the tablew is fit for going live. Tough sourcing. Unfortunately, this month I have no time for it. So I'll be back next week, ans pblush it (if you've not done so already). -DePiep (talk) 05:43, 23 May 2022 (UTC)

NUBASE 2020 table: now live

•  Done I've put table {{Decay modes/2020}} live as is, using all data rows (modes) in NUBASE 2020.

See {{Decay modes}} in Radioactive decay § List of decay modes

Edits can be made in live {{Decay modes}}.

Subheaders could be re-entered.

Doc to be updated.

When stable, development-data could be removed.

@MeasureWell and PianoDan: -DePiep (talk) 05:37, 7 June 2022 (UTC)

Table developing

{{Decay modes/2020}} (developing in time), {{Decay modes}} (live version)

  Columns shown in articles (headertext to change)

Research: Decay modes/2020 (changes NUBASE2016 → NUBASE2020 and enwiki notation differences)
sort	code	2020 change	enwiki diff	Mode	Name (wl)	Action	AZ	note (dev)
10	alpha			α	Alpha emission	An alpha particle (A = 4, Z = 2) emitted from nucleus	(A − 4, Z − 2)
20	p			p	Proton emission	A proton ejected from nucleus	(A − 1, Z − 1)
30	2p			2p	Proton emission lbl:2-proton emission 2-proton emission	Two protons ejected from nucleus simultaneously	(A − 2, Z − 2)
40	n			n	Neutron emission	A neutron ejected from nucleus	(A − 1, Z)
50	2n			2n	Neutron emission lbl:2-neutron emission 2-neutron emission	Two neutrons ejected from nucleus simultaneously	(A − 2, Z)
60	epsi		"EC" not in table; see 62	ε	Electron capture	A nucleus captures an orbiting electron and emits a neutrino; the daughter nucleus is left in an excited unstable state	(A, Z − 1)
70	e+	new		e+	Positron emission	A nuclear proton converts to a neutron by emitting a positron and an electron neutrino	(A, Z − 1)
80	b+			β+	β plus decay→ Positron emission	In NUBASE2020, β+ refers to the combined rate of electron capture (ε) and positron emission (e+): (β+ = ε + e+)	(A, Z − 1)
90	b-			β−	β minus decay→ β− decay	A nucleus emits an electron and an electron antineutrino	(A, Z + 1)
100	2b-			β−β−	Double beta decay lbl:Double β decay Double β decay	A nucleus emits two electrons and two antineutrinos	(A, Z + 2)
110	2b+		in enwiki noted as β+β+	β+β+	Double positron decay→ Double β decay	A nucleus emits two positrons and two neutrinos	(A, Z − 2)
120	b-n		new for enwiki	β−n	β−-delayed neutron emission	A nucleus decays by β− emission to an excited state, which then emits a neutron	(A − 1, Z + 1)	(already in NUBASE2016 table)
130	b-2n		new for enwiki	β−2n	β−-delayed 2-neutron emission	A nucleus decays by β− emission to an excited state, which then emits two neutrons	(A − 2, Z + 1)	(already in NUBASE2016 table)
140	b-3n	new in 2020		β−3n	β−-delayed 3-neutron emission	A nucleus decays by β− emission to an excited state, which then emits three neutrons	(A − 3, Z + 1)
150	b+p		new for enwiki	β+p	β+-delayed proton emission	A nucleus decays by β+ emission to an excited state, which then emits a proton	(A − 1, Z − 2)	(already in NUBASE2016 table)
160	b+2p		new for enwiki	β+2p	β+-delayed 2-proton emission	A nucleus decays by β+ emission to an excited state, which then emits two protons	(A − 2, Z − 3)	(already in NUBASE2016 table)
170	b+3p	new in 2020		β+3p	β+-delayed 3-proton emission	A nucleus decays by β+ emission to an excited state, which then emits three protons	(A − 3, Z − 4)
180	b-a		new for enwiki	β−α	β−-delayed alpha emission	A nucleus decays by β− emission to an excited state, which then emits an α particle	(A − 4, Z − 1)	(already in NUBASE2016 table)
190	b+a		new for enwiki	β+α	β+-delayed alpha emission	A nucleus decays by β+ emission to an excited state, which then emits an α particle	(A − 4, Z − 3)	(already in NUBASE2016 table)
200	b-d		new for enwiki	β−d	β−-delayed deuteron emission	A nucleus decays by β− emission to an excited state, which then emits a deuteron	(A − 2, Z)	(already in NUBASE2016 table)
210	b-t	new in 2020		β−t	β−-delayed triton emission	A nucleus decays by β− emission to an excited state, which then emits a triton	(A − 3, Z)
262	CD		not in 2020; same as 260?	CD	Cluster decay	A nucleus emits a specific type of smaller nucleus (A1, Z1) which is larger than an alpha particle	(A − A1, Z − Z1) & (A1, Z1)
305	IT			IT	Nuclear isomer § Decay processes lbl:Internal (isomeric) transition Internal (isomeric) transition	A nucleus in a metastable state drops to a lower energy state by emitting a photon or ejecting an electron.	(A, Z)
310	SF			SF	Spontaneous fission	A nucleus disintegrates into two or more smaller nuclei and other particles, all of which may vary with each decay	variable
320	b+SF			β+SF	β+-delayed fission	A nucleus decays by β+ emission to an excited state, which then undergoes spontaneous fission	β+ & variable
330	b-SF			β−SF	β−-delayed fission	A nucleus decays by β− emission to an excited state, which then undergoes spontaneous fission	β− & variable
900	Not in Table 2020
260	24Ne	new in enwiki (same as CD, 262?)		24Ne	Heavy cluster emission	(already in 2016 table)	[?]	neon-24?
910	epsiepsi	not in NB table	Kr-78, Fe-54	εε	Double electron capture	A nucleus absorbs two orbital electrons and emits two neutrinos – the daughter nucleus is left in an excited and unstable state	(A, Z − 2)	see 2β...
920		in table?			[[Beta decay § Bound-state β− decay]] lbl:Bound-state beta decay Bound-state beta decay	A free neutron or nucleus beta decays to electron and antineutrino, but the electron is not emitted, as it is captured into an empty K-shell; the daughter nucleus is left in an excited and unstable state. This process is a minority of free neutron decays (0.0004%) due to the low energy of hydrogen ionization, and is suppressed except in ionized atoms that have K-shell vacancies.	(A, Z + 1)
930		in table?			Electron capture with positron emission	A nucleus absorbs one orbital electron, emits one positron and two neutrinos	(A, Z − 2)	mode = "blank"
940		in table?			Internal conversion	Excited nucleus transfers energy to an orbital electron, which is subsequently ejected from the atom	(A, Z)
1		not in NB table				[not a decay mode; added for completeness]	—
11	beta	test		β	β-test	[β added for testing only]		sole-β is not a mode
62	EC	not in NB table		EC	Electron capture	Same as 60?, ε	(A, Z − 1)
102	2b-		see 100	β−β−	Double beta decay	β− (old enwiki notation)		notation diff
112	2b+		see 110	β+β+	Double positron decay→ Double beta decay	2β+ (old enwiki notation)		notation diff
3	obsstable	not in NB table	e.g. Isotopes of mercury#Hg-198	observ. stable	observationally stable→ observationally stable	[not a NB decay mode; added for completeness]	—	NOT in NUBASE2020

References

"Radioactive materials" listed at Redirects for discussion

An editor has identified a potential problem with the redirect Radioactive materials and has thus listed it for discussion. This discussion will occur at Wikipedia:Redirects for discussion/Log/2022 April 28#Radioactive material until a consensus is reached, and readers of this page are welcome to contribute to the discussion. Oiyarbepsy (talk) 05:12, 28 April 2022 (UTC)

List of decay modes: Cluster decay

@DePiep: Would it be possible to edit the line Cluster decay in your table? Normally I would do it myself, but I cannot find the source code to modify. Suggested changes: 1. Mode column: Delete 24Ne because it is not the only possible cluster emitted. 2. Action column: Add at the end: Examples C-14 and Ne-24. (These are 2 of the most frequent examples as per the list in the article Cluster decay. Dirac66 (talk) 16:02, 29 October 2023 (UTC)

@Dirac66: DePiep has been community banned since May, so he's not able to respond. I think I've done what you asked. Double sharp (talk) 08:44, 28 November 2023 (UTC)

@Double sharp: Yes, you have corrected the table as I asked. Thank you for the correction and also for pointing it out. I did not notice the change since because it does not appear in the revision history. Whatever method you used to correct the table is quite mysterious for someone used to standard Wikipedia edits, and if I now look at a revision before the date of the request above (29 Oct 2023) the system claims that this line was already as it is now, which is not true. I am glad you knew how to do it. Dirac66 (talk) 22:58, 28 November 2023 (UTC)

Wiki Education assignment: 4A Wikipedia Assignment

This article was the subject of a Wiki Education Foundation-supported course assignment, between 12 February 2024 and 14 June 2024. Further details are available on the course page. Student editor(s): Alliemoreno (article contribs). Peer reviewers: Samiam25.

— Assignment last updated by Ahlluhn (talk) 00:57, 31 May 2024 (UTC)

a snowfield on a mountain?

The article claims, without a reference, that radioactive decay is analogous to an avalanche from a snowfield on a mountain. The entire paragraph mixes simple classical ideas with bogus quantum ones. It talks about entropy and "over a larger number of quantum states". The energy of decay is down hill even ignoring entropy as far as I know. That's one of its most interesting characteristics. Radioactive decay is exactly not like classical systems. Am I wrong here? Johnjbarton (talk) 01:52, 31 May 2024 (UTC)

The paragraph following our snowfield seems equally dubious to me.

• Such a collapse (a gamma-ray decay event) requires a specific activation energy.

I've never heard of this. The paragraph ends with a reference to

• Milonni, Peter W. "Why spontaneous emission." Am. J. Phys 52.4 (1984): 340-343.

which is about spontaneous emission. As far as I can tell the article never mentions radioactive decay. Johnjbarton (talk) 02:26, 31 May 2024 (UTC)

Characteristic lifetime effects.

@Ehrenkater Here is the paragraph I based the lifetimes on

• All of the strong, the electromagnetic and the weak interactions are relevant to the decay of nuclei. Though there are a large variety of decays, the time scale of the lifetime associated with them is of the order of 10−21 s, 1 ps = 10−12 s, and 1 min, respectively, reflecting the difference among their strengths.

To me that means the characteristic time associated with weak interaction is on 1 minute. As for the dubious mark: "The strong interaction produces attraction between nucleons, and is thus responsible for nuclear stability and when it fails[dubious – discuss] the lifetimes are of the order of 10-21s." what is your suggestion? Johnjbarton (talk) 21:39, 3 October 2024 (UTC)

• One simplistic question here: if the weakest of the 3 interaction types leads to lifetimes of the order of 1 minute, why are there also much longer lifetimes of the order of billions of years? Dirac66 (talk) 22:57, 3 October 2024 (UTC)

  yes, seems pretty lame. I will look for a different reference.

  Mabye we should delete this section altogether. When I arrived it had poor refs and puzzling claims, and now it's different but the same ;-) Johnjbarton (talk) 23:05, 3 October 2024 (UTC)

  This ref is a lot clearer:

  • Pfützner, M., Karny, M., Grigorenko, L. V., & Riisager, K. (2012). Radioactive decays at limits of nuclear stability. Reviews of modern physics, 84(2), 567-619.

  Johnjbarton (talk) 23:41, 3 October 2024 (UTC)

Thanks. The abstract for the article by Pfutzner et al. is available at https://journals.aps.org/rmp/issues/84/2 Free access to the full article requires logging in via an institution. Dirac66 (talk) 00:19, 4 October 2024 (UTC)

Yeah, sorry. Reviews of Modern Physics is the only thing I subscribe to. In this case I think you can find it on citeseer or arXiv, see google scholar search result Johnjbarton (talk) 01:30, 4 October 2024 (UTC)

It is not true that "the time scale of the lifetime associated with them is of the order of 10−21 s, 1 ps = 10−12 s, and 1 min, respectively". First, the half lives, or mean lives, whichever you prefer, vary over a huge range, and none of them has a "characteristic lifetime". The reference to a specific time interval, such as 1 minute, is not grounded in fact. Second, each type of decay is related to a balance between the strong, electromagnetic, and weak interactions, and not with just one of them, so "respectively" is highly misleading.

Next, the strong interaction does not "fail", it is there all the time, so the mention of "failure" is also highly misleading (and dubious). The stability of a nucleus depends on the balance between the various forces, and it is this that determines nuclear stability or instability, and not the strong force alone.

I agree that we should delete the section as it is, and maybe start again. Ehrenkater (talk) 10:07, 4 October 2024 (UTC)

Or I started over.

When we collide some atoms to create a new element, in some case the strong force overcomes the other forces. In other circumstances it "fails" to overcome the other forces. It seems like a reasonable way to explain it to me, but I agree that my first attempt implied a change in the strong force, which does not occur. Anyway that is now gone we can try again. Johnjbarton (talk) 16:20, 4 October 2024 (UTC)

Ok I completed a short section that primarily acts to link other articles, a good goal for now. Please review.

The Pfützner review has a figure showing characteristic times for gamma and beta competing with particle emission. While is interesting and could be explained, they don't really discuss it. What we need for more on this is a ref that discusses the competition. Johnjbarton (talk) 00:27, 5 October 2024 (UTC)