Talk:Actinide/Archive 1

Archive 1

lanthanide and actinides

See the, modfifcation I have proposed in French (my English is not good enough for on line modifying): Lanthanides and Actinides are similar, only when they are at the same oxidation state. This make difference for Pa, U, Np, Pu and Am, which can be stable at +5 and/or +6 oxidation states, while Lanthanides cannot be oxidised that much.

Wikipedia's version of the periodic table has been changed to conform to IUPAC. Flying Jazz 02:00, 23 Jun 2005 (UTC)

I changed the article (and lanthanide-article) to use IUPAC convention and to make it consistent with Wikipedia peridic table. --Levil 02:05, 23 August 2005 (UTC)

Phase diagram

How is it that the x-axis of this plot is continuous, rather than discrete? Moreover, the "complex cubic" phase lies between two elements. What does that mean? 199.64.0.252 20:14, 23 July 2007 (UTC)

Move Actinide to Actinoid

I propose that this article be moved to Actinoid and that Actinide be redirected there. Squideshi 04:14, 26 August 2007 (UTC)

Agreed, the same should be done to Lanthanide. Some minor changes would be required in the text during this move to ensure consistency. Polyamorph (talk) 16:31, 29 April 2008 (UTC)

I'm not sure common usage has followed the IUPAC change. --JWB (talk) 18:02, 4 August 2009 (UTC)

In my experience common usage is changing to follow the IUPAC change. It is also appropriate for wikipedia to use the correct terminology. Polyamorph (talk) 10:54, 5 August 2009 (UTC)

Do you have a Wikipedia policy link describing what "correct" means in this case? --JWB (talk) 18:30, 5 August 2009 (UTC)

I don't know the policy well enough but for self-consistency wikipedia should follow the guidelines detailed by international bodies that set standards. People may choose not to use the nomenclature but it's rather like the International System of Units where at times entire countries choose not to follow the standard but neverthess it is still the internationally accepted way of doing things. Polyamorph (talk) 21:16, 9 February 2010 (UTC)

I checked the policy, it would appear in Wikipedia:Naming conventions (chemistry) that the IUPAC terminology is preferred as the "correct" terminology in chemistry related articles. Although this isn't explicitly stated it seems when in doubt use IUPAC. Polyamorph (talk) 21:32, 9 February 2010 (UTC)

Please see this community discussion on this issue. Polyamorph (talk) 07:29, 10 February 2010 (UTC)

[PuO₅]^3-

According to the article Pu can also lose all its valence electrons, as in [PuO₅]^3-. This is only Pu(VII), though, with still one electron in the valence shell. Existence of Pu(VIII) is questionable to me, according to an inorganic chemistry book of 2001 such compound has not yet been prepared. Thus, a reliable source should be added to support the claim of an octavalent Pu compound (with the appropriate formula). Until this is done I am changing the above sentence to refer to Np(VII). Szaszicska (talk) 10:03, 21 August 2010 (UTC)

Superb

Article... well done Victuallers (talk) 09:06, 27 October 2010 (UTC)

Can some one please fix the main page?

Wikipedia's main page says that most actinides glow because of their radioactivity (example pictured)?". This is not true, can someone please fix it? Paul Studier (talk) 17:40, 29 October 2010 (UTC)

Doesn't it read some actinides glow because of their radioactivity (example pictured)? Polyamorph (talk) 18:36, 29 October 2010 (UTC)

I see that you changed it in the DYK template above, it doesn't appear to be on the main page now. I'm not even sure why this was a DYK, I thought that was meant to be reserved for brand new articles. Polyamorph (talk) 18:45, 29 October 2010 (UTC)

Yes, I wondered why it was a DYK. I just couldn't bear to have an error that promotes the view that everything radioactive glows. Updating the template here did not propagate to the main page. Paul Studier (talk) 21:54, 29 October 2010 (UTC)

Americium and curium

There are discussions regarding americium and curium's natural occurence at Talk:Americium and Talk:Curium. Lanthanum-138 (talk) 05:35, 27 May 2011 (UTC)

Diagram

This diagram contains 2 obvious errors: P for Pu and M³⁺ (blue) for, I guess, M⁵⁺. I don't have a PNG editor (which one is recommended?), so I can't do the mods myself. Petergans (talk) 17:56, 22 July 2011 (UTC)

Fixed my typos (I keep the original Origin file). Thank you! Materialscientist (talk) 01:17, 23 July 2011 (UTC)

File:KKG Reactor Core.jpg Nominated for Deletion

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Actinides and Transuranium elements

I read that these are "overlapping groups", in the article, and on this talk page also. But you missed an important point. Actinides is a chemical classification: this group is formed due to similarity in electron configurations and by occupation of a certain place in the periodical system. And Transuranium elements is something of a nuclear classification, because primordial occurrence on Earth is ultimately based on the nuclear stability. So, we have an example where some en.WP users' desire to decorate an article with a star resulted in improper content disposition. Most of this content, starting with the mushroom cloud picture, ought to belong to "Transuranium element" article. Only things related to chemistry should remain in "Actinide", because it is a property of atoms, not nuclei. There are not "overlapping groups", but indeed different topics: chemistry and nuclear physics. So, do we write an encyclopedia, or collecting stars? Incnis Mrsi (talk) 22:29, 22 February 2012 (UTC)

I expanded this article only because it was in a disastrous state (as many other articles - there is no "schedule" for their cleanup) and there was already a GA at ru.wiki to take material from - GAN was unexpected and accidental in many ways. Your explanation is logical, but is just an explanation - those groups overlap in the periodic table no matter what. Your help with expanding transuranium element is truly welcome, your insinuations are not. Materialscientist (talk) 22:59, 22 February 2012 (UTC)

In principle, folks in ru.WP made the same mistake, but ru:Актиноиды seems to be relatively good in chemistry, although Actinides is not. And both Russian and English articles downplay the most important problem about actinides as a classification: these elements are similar to lanthanides only in +3 oxidation state (or maybe in others which exist for corresponding elements of Period 6), but Period 7 shows more diversity in oxidation states, which is not like lanthanides but similar to typical d-elements. This gap is quite unexpected, because I know certainly that such sources exist, in Russian language namely, and probably in English too. So, the state of the article is maybe not disastrous, but quite poor. Incnis Mrsi (talk) 08:13, 23 February 2012 (UTC)

I don't see the problem with the article, there is always room for improvement in a GA article and if a few sentences need clarifying then fine, feel free to do so. As a whole the article clearly satisfies it's aim of providing detailed factual information on the Actinides.Polyamorph (talk) 09:27, 23 February 2012 (UTC)

The problem is that I understand what are "the Actinides" differently than Polyamorph does. To me, it is an approach to classify chemical properties of elements between actinium and lawrencium, and the article should focus on properties which these element share, as well as on differences to d-block elements and the analogy to lanthanides. To Polyamorph, is is apparently something like 20th century, an arbitrarily chosen group of 15 adjacent metallic elements without emphasizing any special aspect of their properties. Maybe I will try to translate some chemistry from Russian, and move most of nuclear stuff to transuranium element and other articles where it would be appropriate, but I expect a critical response. Incnis Mrsi (talk) 09:57, 23 February 2012 (UTC)

My periodic table has the actinides as the chemical elements Ac to Lr. As such the wikipedia article on the actinides should deal with these elements - which it does. It should deal with both nuclear and chemical properties of these 15 elements. Sure there is some overlap with transuranium element but that doesn't mean all the nuclear properties belong in that article instead. Polyamorph (talk) 10:10, 23 February 2012 (UTC)

So, imagine such articles as Period 4 element (from K to Kr in my periodic table) and post-transition metal written in the similar fashion, i.e. "to deal with these elements". Radioactive decay chains ending in Pb and Bi in "post-transition metal" would be even more funny than nuclides' table in "Period 4 element". Incnis Mrsi (talk) 11:46, 23 February 2012 (UTC)

The nuclear properties of the actinides are a major aspect of these elements (because it is a major application of these elements) and deserve to be covered in the main article, along with their chemical properties. The nuclear properties of the period 4 elements or post-transition metals are not important for similar reasons and do not need to be covered in the respective articles. Double sharp (talk) 06:22, 22 April 2012 (UTC)

Just a word of caution, ru:Актиноиды is not stronger, it merely contains more material which I removed and amended while translating because of problems with consistency and references. More problems were revealed during DYK and GAN reviews. I didn't like the structure of the ru.wiki article, and it was rather incomplete, covering only some actinides for some properties (try reading this article and compare it with individual en.wiki articles on those actinides, which are generally better). I recall being rather unhappy with the overall article content after translation, but it was still better than what we had before. Materialscientist (talk) 11:50, 23 February 2012 (UTC)

Lawrencium

It never seems to make sense to include Lawrencium in the series.

As can be seen in the Janet periodic table, the element 103Lr Lawrencium is not a part of the actinide series, but rather the first element of the following 2 + 4 + 4 = 10 element 103 - 112 series. So we're dealing with a tempest in a teapot.WFPM (talk) 19:26, 8 June 2012 (UTC)

Consistency of stability data

The problem with the atomic stability data for the actinides is that it starts out for the first 7 elements in a consistent manner, with the odd Z elements having the OE isotopes and the even Z elements having the EE isotopes with the longest stability halflives. But then it changes for the even Z elements to where the EO elements start having the longest stabililty halflives which is not an understandable situation and leads to a doubt about the data. This situation is worthy of consideration anf hopefully an explanation.WFPM (talk) 19:45, 8 June 2012 (UTC) And the best way to do it is to start paying more attention to the individual isotope stability characteristic data with probably log second halflife charts and decay manner indications such as I suggested in Talk:Isotopes of lead or something similar.WFPM (talk) 18:05, 9 June 2012 (UTC)

Natural isotopes

How can ²⁵³Cf be present in nature but ²⁵³Es be absent? Burzuchius (talk) 15:58, 27 January 2013 (UTC)

This point was mentioned previously on WT:ELEM. It appears that the experiment that detected natural ²⁵³Cf wasn't sensitive enough to detect natural ²⁵³Es. Of course ²⁵³Es should occur naturally, but I'd prefer that it be directly observed in nature before we add it, instead of predicting its natural occurrence without any sources, even though its existence in nature is almost certain. Double sharp (talk) 11:07, 28 January 2013 (UTC)

See Wikipedia talk:WikiProject Elements/Archive 12#Naturally occurring isotopes of transplutonium elements. Burzuchius (talk) 14:14, 28 January 2013 (UTC)

Shell filling overview

See Talk:Lanthanide#Shell_filling_overview for an overview of the filling irregualarities & Madelung. Could be created for An too. ({{Periodic table (electron configuration lanthanides)}}). -DePiep (talk) 10:55, 24 August 2014 (UTC)

Th³⁺

Greenwood and Earnshaw (2nd ed., p.1277) says it's amber (not blue as we have here). Also, The Chemistry of the Actinide and Transactinide Elements (pp.117–8) notes that the reaction claimed to form Th³⁺ by Klapötke and Schulz is actually thermodynamically impossible. Double sharp (talk) 09:14, 2 September 2015 (UTC)

Abundance

IANAChemist/Geologist or Nuclear Physicist but I had thought that the most abundant Actinides were Thorium and Uranium rather than what the article intro has, Uranium and Plutonium? Anihl (talk) 16:35, 29 October 2010 (UTC)

I can't see where in the intro it says this. The lead states: "Only thorium, uranium and protactinium occur in usable quantities in nature; the other actinides are synthetic elements." Polyamorph (talk) 17:02, 29 October 2010 (UTC)

Oh I see it now, I think it is likely to be correct since significant quantities of plutonium have been produced for nuclear weapons/energy sources. But the statement does need a citation. Whereas the natural abundancy of the actinides is generally quite low. Polyamorph (talk) 17:05, 29 October 2010 (UTC)

But the amount of Pu produced as a derivative of U cannot be greater than the amount of Th in existence naturally, given that the amount of U is smaller than the amount of Th. The conversion of U to Pu produces 1:1 atoms; and while I don't have figures to hand I am not aware that a significant proportion of the U in the Earth's crust is even practically extractable, let alone already extracted and put through a reactor to produce Pu. The cited values for natural abundance here, while varying, do indicate that the amount of naturally occurring Th is several times that of U. (I make the average of these sources 7.63 Th : 1.91 U.) I'm not really sure what point the sentence here is trying to make, but I suspect it's just that U and Pu are the major fissile materials used in reactors and weaponry respectively. Nothing to do with natural abundance. Incidentally, now I read the rest of the article, it states it here too. 84.12.193.103 (talk) 04:03, 30 October 2010 (UTC)

I haven't looked up the article on that, but just reading your comment, I note that we should not compare amount of Th in the Earth crust with the amount of U/Pu in human possession, i.e. mining ratio gets in. Materialscientist (talk) 04:16, 30 October 2010 (UTC)

If you count just reduced metal, or purified oxide form, then I suppose I wouldn't be surprised if there was more Pu than Th. Gah4 (talk) 04:17, 13 November 2016 (UTC)

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Actinide?

What kinds of things contain the elements that are in the actinide series?

The actinide series encompasses the chemical elements that lie between actinium and lawrencium on the periodic table with atomic numbers between 89 and 103 inclusive.

Exactly where the sequence of actinides begins and ends is actually open to debate. Various sources make different and often seemingly arbitrary choices. Thus I feel justified in changing this article for consistency with Wikipedia's own version of the periodic table.
—Herbee 06:33, 2004 Mar 10 (UTC)

"Between" implies exclusive. We should either say "between Radium and Rutherfordium" or "between Actinium and Lawrencium, inclusively." ---Ransom (--71.4.51.150 19:01, 25 January 2007 (UTC))

The Actinide series should only include the 14 elements 89-102, Element 103 Lawrencium is actually a part of the next series.WFPM (talk) 03:37, 19 November 2008 (UTC)

The IUPAC recommendation for the nomenclature of inorganic chemistry says that the actinoids are elements 89-103: Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr. --Itub (talk) 11:59, 24 November 2008 (UTC)

I guess they dont worry about only having 9 elements in the next 10 element series. WFPM (talk) 03:30, 26 November 2008 (UTC)

IUPAC doesn't have a concept of "element series". What they call collective names of groups of like elements consists of non-exclusive categories. So the same element can be a rare earth, a lanthanoid, and a transition metal. --Itub (talk) 07:34, 27 November 2008 (UTC)

I guess I just cant overcome my agravation at them for being complicit in keeping the periodic table so fouled up that some people actually believe in the existence of 15 element series' and/ or 9 element series, instead of the 2, 6, 10, 14 element length of series that is obvious in even their periodic table. WFPM (talk) 15:14, 27 November 2008 (UTC)

According to the topology of the left-step periodic table, which is the irreducible form of any periodic system in accordance with Madelung´s rule, the scientific community should simply skip the outdated notation of the head group elements for the f-block and the d-block elements. Lanthanum and Actinium are genuine and starting elements for the f-block, whereas Scandium, Yttrium, Lutetium and Lawrencium are genuine and starting elements for the d-block. The final evidence to this replacement is the experimental determination of the first ionization energy (IE1) of Lawrencium (Z = 103) and the respective enthalpy of desorption from gold and quartz surfaces. These values are in agreement with theoretical calculations for an assumed ground state configuration [Rn]7s25f147p1, intead of [Rn]7s25f146d1. Thus, 103-Lr is another example with an "anomaly in its electronic ground state configuration", and it cannot be placed in the p-block, because this place is filled up with element 113-Nh (Nihonium). For detailed discussion see the papers by Will B. Jensen, Eric Scerri, Henry A. Bent. — Preceding unsigned comment added by DocWolf (talk • contribs) 17:40, 8 November 2016 (UTC)

You may notice that even Jensen thinks that the ionisation energy argument for Lr is inconclusive, because Ac fits the trend just as well. Lanthanum and actinium make very poor choices to start the f-block because they have never been shown to display any f-character at all in their bonding. It makes far more sense to consider them to be the first members of a d-block interrupted by an f-block spanning Ce to Lu and Th to Lr. Madelung's rule, in any case, tends to predict the wrong subshell ordering for almost all the elements: in the actinides it predicts 7s < 5f < 6d, when the actual order is 5f < 6d < 7s. Double sharp (talk) 03:37, 9 November 2016 (UTC)

The lanthanides and actinides are filling of an f shell with 14 electrons. Do you consider the range from 0 to 13, or 1 to 14, or 1 to 13, or 0 to 14? There are arguments for each choice. Gah4 (talk) 10:05, 21 April 2017 (UTC)

In this way, Enrico Fermi with collaborators, using the first nuclear reactor Chicago Pile-1, obtained significant amounts of plutonium-239, which were then used in nuclear weapons.

The statement In this way, Enrico Fermi with collaborators, using the first nuclear reactor Chicago Pile-1, obtained significant amounts of plutonium-239, which were then used in nuclear weapons. doesn't seem quite right. As well as I know, the early plutonium for bombs came from Hanford. I suppose if there was some from Chicago, that could have gone it, too. Gah4 (talk) 10:09, 21 April 2017 (UTC)

0 or 1?

The question about which elements are actinides makes about as much sense as arguments over arrays in computer languages starting with element 0 or 1. The actinides fill and f shell, so is it elements with 0 to 13 electrons in f, or 1 to 14? Or, as others noted, it could be 0 to 14. (There are computer languages which, when given a dimension of n allow for elements 0 through n.) Elements with 0 through 14 f level electrons have the other shells the same, and an equal right to whatever you want to call them. Gah4 (talk) 14:07, 18 May 2017 (UTC)

The actinides are defined by chemical similarity, not by whichever electron subshells are being filled. If you look at the traditional definition of transition elements (vs. main group elements), you will see that it corresponds to elements with d² through d⁹ (ideally; Cu, Ag, and Au are all really d¹⁰s¹ instead of d⁹s²), omitting 0, 1, and 10 entirely, because Ca, Sc, and Zn do not behave very much like Ti–Cu chemically. When defining the actinides, the most sensible thing is to look for chemical similarity (mostly on analogy with the lanthanides, because the earlier ones are a bit wonky); then Ac–Lr is the most sensible definition. But it's not corresponding to f-electrons that is the important thing here. If you really want to get technical about it, there are minor differences for Ac and Lr because the 5f subshell for them is completely inactive, even for f–f transitions; the same goes for 4f in La and Lu. But that has no bearing on what an actinide is; the category is defined chemically.

However, some authors do try to rationalise the categories of "lanthanides" and "actinides" to the f-block, thus excluding La and Ac because they have no more f-orbital involvement than Ca, Sr, and Ba have d-block involvement. In that sense, yes, Ce–Lu and Th–Lr is a common alternative classification, but in practice La and Ac are always included as well for comparative purposes (as is Y usually for the lanthanides; Sc is much smaller and is a bit of a misfit, neither 3d transition metal nor orthodox rare earth). Double sharp (talk) 14:16, 18 May 2017 (UTC)

Yes. Well, for one, the d shell isn't so deep, such that it has more effect on chemical properties, as you note. But at some point, they go on a paper periodic table, and the little squares have to go somewhere. There seems to be much I'm right and you are wrong for each of the possible ways of naming them. Seems to me that there are a fairly small number of publishers of paper tables, though maybe not all the same. Gah4 (talk) 14:43, 18 May 2017 (UTC)

5f is an interesting case, since it starts out naturally larger (thanks to the radial nodes) and with the relativistic destabilisation of orbitals with high angular momenta it actually shows up in the early actinides and makes them almost like transition metals. (It shrinks in compensation at the end of the actinide series even past the extent for which it happens to the 4f subshell, to the point that No actually has +2 as the favoured oxidation state in aqueous solution.) I'm not sure if the group 3 dilemma hurts it that much, though; I'm certainly on the side of La and Ac going in the main body of the table (so much so that I co-wrote a submission to IUPAC about it with Sandbh, which hopefully goes significantly past "I'm right and you are wrong" ^_^), but I have no problem saying that La is a lanthanide and Ac is an actinide for chemical reasons, and from what I see most authors don't have a problem with that either. The main issue where the shots get fired is whether La and Ac are d-block or f-block elements, and hence where they actually show up in the table; chemically it is not in question that they pattern well with what comes after them and, for the most part, that they belong in their eponymous categories. (I might seriously suggest that La, Ac, Lu, and Lr are not properly "inner transition metals", but in practice no one cares about that.) Double sharp (talk) 14:55, 18 May 2017 (UTC)

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Isotopes

Why are there no paragraphs on the isotopes of Th and Pu? Double sharp (talk) 16:22, 16 June 2017 (UTC)

I believe all the important ones have their own article. I suppose there could be links to those, but there is also a page for each element that links to the isotope pages. Gah4 (talk) 06:48, 28 February 2019 (UTC)

Pyrophoric

Physical properties: "All actinides are pyrophoric, especially when finely divided, that is, they spontaneously ignite upon reaction with air at or below 55 °C" - Is this true? Below 55 °C? That means they self-ignite at 0 K? --Gunnar (talk) 11:41, 1 September 2020 (UTC)

Error in graph?

Just noticed: Isn't there an error in the table or graph for Lr? The table says the longest-lived isotope for Lr(Z=103) is Lr 266. Yet in the isotope graph, there are no isotopes for Lr over 262. — Preceding unsigned comment added by 88.103.29.180 (talk) 22:27, 10 June 2020 (UTC)

Seems the graph predates discovery of ²⁶⁶Lr; should probably be changed. Double sharp (talk) 12:31, 24 January 2021 (UTC)

Actinide vs Actinoid

IUPAC argues that the -ide ending is reserved for a binary compound, such as chlorides or nitrides. The -oid ending means "similar to" as in humanoid or android. Therefore, I do propose to use the new official name first, with the old -ide ending second as a synonym. --Gunnar (talk) 10:18, 1 September 2020 (UTC)

I agree, but judging from Talk:Lanthanide, this seems unlikely to get consensus.

Also: the idea that actinoids are similar to Ac (which is basically a more basic and electropositive La) is kind of a joke. Anyone who believes it should compare chemistries of lanthanum and uranium. Lanthanoids are indeed similar to La. So maybe the -oid ending is not particularly right either. I don't know if this influenced anybody to avoid adopting the new -oid endings, though. Double sharp (talk) 08:34, 24 March 2021 (UTC)

Colors of ions

See the second table in Actinide#Properties. Since the colors are the topic (not an illustration), I have made the bg white for good showing. Now it appears that three ions have no color added at all (per row the leftmmost one, starting with Ac³⁺). I suggest someone adds their color as bg color (which could be white). As it stands now, their colors are "undecided and unexplained". -DePiep (talk) 08:13, 10 November 2019 (UTC)

Maybe this second table could be merged into the big one above it. (Colors row can have multiple subrows). -DePiep (talk) 08:28, 10 November 2019 (UTC)

And, the big table be transposed, so that columns can be sortable for more comparing options. -DePiep (talk) 08:29, 10 November 2019 (UTC)

They are colourless. Think of plain water. Double sharp (talk) 08:35, 24 March 2021 (UTC)