Clark responded, making the point raised by this Author at the beginning of the chapter. The discourse was based upon the defect of the 18-column form of the Periodic Table, necessitating 14 elements to be ripped from their rightful place and “dumped” beneath [8]:
… I now favor relegating the flyleaf [18-column] forms to history and shifting the resulting debate to which of the long-form tables is best. There will still be arguments as to which long-form table to use, but these will be healthier arguments than the electron shift agonies of past decades.
The feud continued into 2009. Jensen replied to Lavelle’s article [9]:
For obvious reasons I feel compelled to comment on the recent commentary by Lavelle on the placement of La and Ac in the periodic table as I feel that it is not only based on inconsistent reasoning but also contains a serious distortion of the contents of my original article dealing with the subject.
In the same rebuttal, Jensen concluded with [9]:
Finally, with regard to Lavelle’s assertion that in his accompanying letter that he speaks for the silent majority who have been cowed into submission by the vocal proponents of the Lu-Lr alternative, I can only say that discussion of this subject is welcome, but for such discussion to be profitable it must be both logically consistent and relevant.
Lavelle’s response was published on the following page. He reiterated that, in his view, Jensen’s assignments were only accepted by a minority. Lavelle continued [10]:
The point of my discussion on lawrencium was that those who insist on placing lutetium and lawrencium in the d-block, and insist that others do also, are selective in the literature they cite to support the claim.
The personal enmity came through in the closing sentence [10]:
Jensen appears to be unaware of the self-righteous content of some of his articles in this Journal that detract from his otherwise many historically informative publications.
Laing intervened. Jensen, in his 2008 contribution to the debate [5], had cited the Periodic Table from Ephraim’s textbook Periodisches System der Elements. Laing pointed out that in the 6th English translation, Fritz Ephraim’s Inorganic Chemistry [11], the lanthanoids were displayed differently. He added [12]:
In the 25 years that passed between editions, the La-Lu problem was no closer to solution. Another 55 years have now gone by and the debate rages on: plus ça change, plus c’est la même chose…. Arguing about the “right place” for thorium and uranium (or La and Lu or Ac and Lr) in a f- or d-series seems purposeless. Why “should” thorium, [Rn]6d27s2, be best placed in the f-block? … there is no ideal or perfect periodic table.
Then Scerri joined the debate. In his commentary, he reiterated the point by Clark (and by this Author) [13]:
It is generally agreed that the conventional or medium-long form table [that is, s-d-p, more often called the short form] continues to survive only because it is more conveniently reproduced in textbooks and wall-charts than the long-form table. The medium-long form table [18-column] relegates as many as 28 elements to a kind of disconnected footnote, and thereby allows one to keep the periodic table relatively slim and having 18 columns. The long-form table, which some textbooks feature, consists of a width of 32 columns. But on the plus side it includes the lanthanoids and actinoids in their rightful place within the main body of the table. More importantly perhaps, it maintains an uninterrupted and increasing sequence of atomic number.
The exchanges ceased, though whether it was because exhaustion had set in, or because the Journal of Chemical Education had decided to bar any future acrimonious exchanges (as with the hydrogen placement issue — see Chapter 3), it is not known.
IUPAC Becomes Involved
It was in 2009 that Leigh felt it necessary to clarify the position of the International Union of Pure and Applied Chemistry (IUPAC) on the various periodic table designs in the pages of Chemistry International [14]:
In fact, IUPAC has not approved any specific form of the periodic table, and an IUPAC-approved form does not exist, though even members of IUPAC themselves have published diagrams titled “IUPAC Periodic Table of the Elements.”
Leigh briefly mentioned the Group 3 issue [14]:
As the long form [18-column] places them, the lanthanoids and actinoids sit rather uncomfortably each in a single place, but should lanthanum and actinium be grouped directly with their congeners?
He, too, alluded to the fact that, with what he called the long–long form (here called simply the 32-column form) the Group 3 placement issue did not arise.
Citing Leigh, Scerri argued that IUPAC did need to take a stand on the Group 3 issue [15]:
I propose that IUPAC should in fact take a stance on the membership of particular groups even if this has not been the practice up to this point.
As some 18-member Periodic Tables showed Group 3 as Sc–Y–La–Ac and others Sc–Y–Lu–Lr, Scerri felt the issue needed to be definitively resolved [15]:
This has led to a situation in which chemistry students and professionals alike are often confused as to which version is “more correct” if any.
Scerri pointed out that if the long form of the Periodic Table was written out, then keeping the f- and d-blocks intact, lutetium and lawrencium would naturally occur beneath scandium and yttrium. The Sc–Y–La–Ac alternative could only be structured if, in the long form, the d-block elements of Group 3 (scandium and yttrium) were shifted over next to Group 2, breaking up the transition metal series.
Jensen then rejoined the debate, repeating his 1982 position that lutetium and lawrencium should be assigned to the d-block and lanthanum and actinium as the first members of the f-block.
