Talk:Lawrencium/Archive 1

Archive 1

speculative chemical/physical properties

I've deleted the following text:

(in elementbox) appearance: unknown, probably silvery
white or metallic gray

(in elementbox) phase: presumably a solid

(under Notable characteristics, appearance is), however it is most likely silvery-white or gray and metallic

Since ability to produce more than a few atoms is so limited, these are mostly untestable assertions (and furthermore, there is no citation even for the speculations).Kingdon 21:44, 11 February 2007 (UTC)

Electron configuration typo?

Shouldn't the electron configuration for Lawrencium be [Rn]5f¹⁴ 6d¹ 7s²? I'm not a chemist (just studying it en route to an engineering degree), but that is how it is shown on other chemistry sites.--H-ko 04:55, 3 September 2006 (UTC)

Reference is electron configurations of the elements (data page). They're all more or less educated guesses, I guess. NIST's data seems the most recent and reliable. Femto 10:50, 3 September 2006 (UTC)

Thanks for the information; I suppose the differences are due to the uncertainty.--H-ko 09:36, 4 September 2006 (UTC)

I agree with the first comment : Lr has an electronic configuration 7s2 5f14 6d1, according to Klechkowsky rule, and not 6p1. I think there is a mistake in electron configurations of the elements (data page). Darrigan

There is no mistake: the electron configuration is the one reported in Phys. Rev. A 52, 291-296 (1995) and comes from relativistic ab initio calculations. The Klechkowsky rule is empirical and has exceptions. Real electron configurations normally come from spectroscopic observations, but in this case the best we have, as far as I know, are these ab initio calculations. --Itub 17:26, 3 December 2007 (UTC)

i dont know how to change but should be

in the box of the element it should be 5d subscript 1 not p i dont know how to change that but it has the actual right fact farther down page —Preceding unsigned comment added by 172.165.129.182 (talk) 08:41, 4 December 2008 (UTC)

Nuclear structure

The atom of 103Lr Lawrencium may be characterized as having a structure consisting of an accumulation of 103 deuterons plus a variable number of excess neutrons. Its longest halflife isotope is reported to be OE103Lr262 with 56 extra neutrons and a halflife of 3.6 hours (= 10E^4.116 log seconds). Its maximum isotope stability line characteristic is A = 3Z - 47. Its direction of decay is toward either EE102Nb262 Nobelium with 58 extra neutrons and A = 3Z - 44 (ec or B+ emission), or else backward by alpha emission to OE101Md258 with likewise 56 extra neutrons and an A = 3Z - 45 stability characteristic. The OE101Md258 isotope is noted to have the longer halflife.WFPM (talk) 20:41, 20 May 2012 (UTC)

We can also note that 103Lr Lawrencium is the first element of the 2 + 4 + 4 = 10 transition element series after the actinide series, which ends with element 112.WFPM (talk) 15:17, 21 May 2012 (UTC)

Talk

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Why did the symbol change from Lw to Lr in '63?

and was is in 1963 or 1997 ? — Preceding unsigned comment added by 194.250.184.205 (talk) 08:44, 28 June 2012 (UTC)

Nucleosynthesis

Huge parts of the "Nucleosynthesis" and "Isotopes" paragraph are available at Isotopes of lawrencium as well. I'd suggest to remove redundant parts from the Lawrencium article and simply keep the link to the isotopes. Soulblydd (talk) 15:15, 7 May 2014 (UTC)

 Done, along with a major rewrite of the article. Double sharp (talk) 13:46, 19 August 2014 (UTC)

GA Review

This review is transcluded from Talk:Lawrencium/GA1. The edit link for this section can be used to add comments to the review.

Reviewer: Parcly Taxel (talk · contribs) 09:53, 9 September 2014 (UTC)

Once this goes to GA, we'll have an actinide GT. Parcly Taxel 09:53, 9 September 2014 (UTC)

GA review – see WP:WIAGA for criteria

1. Is it reasonably well written?

   A. Prose is "clear and concise", without copyvios, or spelling and grammar errors:

   B. MoS compliance for lead, layout, words to watch, fiction, and lists:

2. Is it factually accurate and verifiable?

   A. Has an appropriate reference section:

   B. Citation to reliable sources where necessary:

   C. No original research:

3. Is it broad in its coverage?

   A. Major aspects:

   B. Focused:

4. Is it neutral?

   Fair representation without bias:

5. Is it stable?

   No edit wars, etc:

6. Does it contain images to illustrate the topic?

   A. Images are tagged with their copyright status, and valid fair use rationales are provided for non-free content:

   B. Images are provided if possible and are relevant to the topic, and have suitable captions:

7. Overall:

   Pass or Fail:

Lead

• "Twelve isotopes of lawrencium are currently known: the most stable is ²⁶⁶Lr with a half-life of 11 hours; but the shorter-lived ²⁶⁰Lr (half-life 2.7 minutes) is most commonly used in chemistry because it can be produced on a larger scale." Colon should be a semicolon, semicolon should be a comma.
  •  Done Double sharp (talk) 14:13, 9 September 2014 (UTC)

History

• "Eighteen tracks were noted, with decay energy around (9 ± 1) MeV and half-life around 1⁄4 s; the Berkeley team noted that while the cause could be the production of an isotope of element 103, other possibilities could not be ruled out."
  •  Done Double sharp (talk) 14:13, 9 September 2014 (UTC)

Characteristics -> Chemical

• "It has been speculated that the 7s electrons would be are relativistically stabilized, so that in reducing conditions, only the 7p_1/2 or 6d electron would be ionized, leading to the monovalent Lr⁺ ion."
  •  Done Double sharp (talk) 14:13, 9 September 2014 (UTC)

Atomic

• "If the s²p configuration is correct, then lawrencium could not cannot be regarded as a transition metal under the IUPAC definition ("An element whose atom has an incomplete d sub-shell, or which can give rise to cations with an incomplete d sub-shell."), …"
  •  Done Double sharp (talk) 14:13, 9 September 2014 (UTC)

Parcly Taxel 09:53, 9 September 2014 (UTC)

Correct no. of electrons per shell?

Is it: a) 2, 8, 18, 32, 32, 8, 3 as in the infobox, or b) 2, 8, 18, 32, 32, 9, 2 as in the Bohr model given in the text? If it is (a) that would make Lawrencium the only element with a valence number of 3 that is not in the boron group.Titus III (talk) 10:16, 15 February 2009 (UTC)

The one experiment that was conducted to check this was inconclusive, but all modern calculations unanimously support (a) AFAIK. Double sharp (talk) 21:44, 21 August 2014 (UTC)

Decay of 262-Lr

I removed the statement that ²⁶²Lr decays to ²⁵⁶No. Perhaps it should be ²⁵⁸Md (alpha decay) but in any case emission of significant/majority amounts of ⁶H in spontaneous fissions seems very improbable. Dajwilkinson 01:50, 18 August 2007 (UTC)

²⁶²Lr can indeed decay to ²⁵⁸Md via alpha decay, but the primary decay mode is electron capture to ²⁶²No. Perhaps ²⁵⁶No is a typo, doubtless long gone from the article by now. (I'm aware that this response comes seven years late.) Double sharp (talk) 21:46, 21 August 2014 (UTC)

Why change from Lw to Lr?

So why was the symbol changed from Lw to Lr? - David Gerard (talk) 23:08, 5 August 2009 (UTC)

Whenever possible, the symbol for a new element is chosen to have the first letters of the first two syllables. If it is not possible, there is free choice, as long as the symbol doesn't clash with that of any other element. There have been some exceptions (Rf and Db are the only ones that are superheavy elements, when I think IUPAC came up with this guideline), but the newest elements all conform to this rule. Md and Lr were changed from Mv and Lw, likely because of this. Double sharp (talk) 13:11, 1 October 2013 (UTC)

I've never heard of this guideline (nor is it mentioned in Symbol (chemistry)); do you have a reference for it? Only 14 elements below uranium fulfill this syllable rule (w.r.t. the English resp. Latin name), and only 10 out of the 22 named transuranium elements do. (For most of the other superheavies, the corresponding symbol was already taken, but not for Np, Rf and Db.) There's twice that many (49) elements which use the first two letters of the element's name, which is a more natural "rule" IMO.--Roentgenium111 (talk) 14:51, 19 August 2014 (UTC)

Only from John Emsley's Nature's Building Blocks (2011 edition), which on p. 279 states: "The original chemical symbol for lawrencium was Lw, but this was changed in 1963 to Lr by the Committee on Nomenclature of Inorganic Chemistry, in order to comply with a new IUPAC ruling which said that the second letter of an element symbol should preferably be a consonant, and in multi-syllable names, it should be chosen from the first letter of the second syllable if possible." Double sharp (talk) 15:05, 19 August 2014 (UTC)

Thanks for the quick reply. In principle, I would expect Emsley to be a reliable source; but on page 3 he actually states my "first two letters" rule, and then the "syllable" rule for "new" elements, without noting the obvious contradiction between the two "rules". Also, if the syllable rule was instated in 1963, it's strange to retroactively change Lw, but allow the next two discoveries (Rf, Db) to break the rule for no obvious reason.--Roentgenium111 (talk) 16:55, 19 August 2014 (UTC)

I agree, it's very odd. In the article I avoided mentioning any reason for the change because of what you pointed out. Double sharp (talk) 20:32, 19 August 2014 (UTC)

Fair enough; it would be nice to have a (reliably sourced) reason behind the change in the article, though. Is it possible that the "Lw" symbol was only suggested but never confirmed by the IUPAC? This seems to have been the case with mendelevium, whose symbol was changed in 1957 prior to the purported establishment of the rule in 1963: According to the IUPAC report, Mv was only the symbol "first proposed", so apparently not yet accepted. --Roentgenium111 (talk) 18:19, 24 August 2014 (UTC)

I found a source! "Lawrencium - the atomic number is 103 and the chemical symbol is Lr. The original chemical symbol was proposed as Lw but it was changed because "W" is an unusual occurrence in many languages and it is a cumbersome spoken word. The name derives from the American physicist [Ernest O. Lawrence], who developed the cyclotron." Double sharp (talk) 04:05, 22 August 2015 (UTC)

2005 comment

Article changed over to new Wikipedia:WikiProject Elements format by maveric149. Elementbox converted 10:14, 15 July 2005 by Femto (previous revision was that of 04:47, 23 June 2005).

when I get around to making this an FA

A good TFA date would be 14 Feb 2021 (60th anniversary of discovery). Double sharp (talk) 10:55, 14 February 2018 (UTC)

OK, so that's not likely... Double sharp (talk) 13:54, 12 February 2021 (UTC)

Nonetheless, it at least made it to OTD. ;) Double sharp (talk) 07:15, 14 February 2021 (UTC)