Janet table

Web Elements explains the periodic table of elements, and includes links to alternative tables, like the Janet table of elements. Each element has a Web site with a general description, but also features more in-depth information, like nuclear, elemental, and electronic properties. 

FIGURE 10.13 The left-step or Janet table. Numbers on the right represent values of + ... 

In addition to the short and long forms of the modern periodic table, another increasingly popular display is called the left step or Janet periodic table. Do an Internet search to find a representation of this form. Why is it called a Janet table Provide a reference in your answer. 

The proposed new table retains most of the feature of the Janet left-step table but does not commit one to placing helium in the alkaline earths. The regular form of the table represents an advantage over the medium-long form and the closer connection with electron-shell filling that the left-step table offers is maintained with the small disadvantage that two values of n + i, namely I and 2, appear in the same first row. 

This form of the periodic table is shown in Figure 1. Although it is often assumed to have a quantum mechanical origin it was first proposed on purely esthetic grounds by the Frenchman, Charles Janet [23]. But in a quantum mechanical guise it takes on a new lease of life, as will be explained shortly. 

The problem is no longer the validity of Mendeleev s system, but the best way to represent it. Should it be the original short-form table with 8 columns, the familiar medium-long form with 18 columns, or perhaps even a long-form table with 32 columns, which more naturally accommodates the rare earth elements Into the main body of the table Altanahvely, some favor pyramidal tables, while others advocate the left-step form proposed by diaries Janet in the 1920s. Theodor Benfey and rhilip Stewart have proposed continuous spiral models. Hundreds, possibly even thousands, of periodic systems have been proposed, and each has its ardent supporters. 

Turner, Janet. [Emerald table] Meditation on the Emerald Tablet. Alchemy J 4, no. 2 (Autumn 2003). rhttp //www.alchemvlab. com/AJ4-2.html. 

C. Janet, Chem. News 138 (1929), 372 and 388 for a text of Janet s original paper, see www.periodic-table.net. 

Table 5a Worldwide Charged Particle Patients Totals (HTCOG—Hadron Therapy Cooperative Group Janet Sisterson, 2001)...

In 1926, Goldschmidt demonstrated the analogies between the elements Th, Pa, U and the lanthanides on the basis of the observation that the volumes of Th and U showed the same contractions as the ions of the lanthanide series. Striking early examples of periodic tables in which actinium, thorium, protactinium, and uranium are considered as homologues of the rare earths lanthanum, cerium, praseodymium, and neodymium are the circular system and left-step table of Charles Janet (Janet, 1929). 

It should be noted that although for decennia lanthanum and actinium could be found below yttrium in most periodic tables, some authors have placed lutetium below yttrium in the past. For instance, in the periodic table of Werner (1905a,b), there is an open place below yttrium at the position where lutetium is expected, but it should be realized that at that time lutetium had not yet been discovered (this was in 1907). However, Werner did not consider lanthanum as a homologue of yttrium, because of the differences in chemical properties between these two elements. Also in the circular system of Janet (Figure 28), the left-step table of Janet (Figure 32) and in the periodic table of Bohr (Figure 21), lutetium was placed below yttrium. 

Jahn-Teller distortion, 396, 398 Janet, Charles, 73 circular system 73 Janet periodic table, 83... 

An altemative representation of the periodic table, as proposed by Charles Janet, 1928. 

T1.2 Your coverage of early proposals for the periodic table should at least include DObereiner s triads, Newlands Law of Octaves, and Meyer s and Mendeleev s tables. From the modem designs (post-Mendeleev) you should consider Hinrichs spiral periodic table, Benfey s oval table. Janet s left-step periodic table, and Dufour s Periodic Tree. 

But I conclude with a less controversial proposal. Let us imagine that the various representations of the periodic system he on a continuum. At one end of thk continuum is the unruly Rayner Canham table (figure 10.14) that attempts to do justice to many unusual relationships of the kind that have been highhghted in this chapter. At the other end of the continuum hes what I call the Platonic periodic table, or what is usually called the left-step or Janet periodic table (figure 10.13). Somewhere near the middle of thk continuum of representations, one can locate the currently popular medium-long representation. It is not altogether surprising that thk fbrm has been so popular since it appears to capture the correct... 

C. Janet, The Helicoidal Classification of the Elements, Chemical News, 138, 372— 374, 388-393,1929 L.M. Simmons,The Display of Electronic Configuration by a Periodic Tabic, Journal of Chemical Education, 25, 658, 1948 R.T. Sanderson, A Rational Periodic Table,Joumul of Chemical Education, 41,187—189,1964 G. Katz,The Periodic Table An Eight Period Table For The 21st Centrury, The Chemical Educator, 6, 324—332, 2001 E.R. Scerri, Presenting the Left-step Periodic Table, Education in Chemistry, 42,135—136, 2005. 

Charles Janet seems to have been the first author to publish this form of table. C. Janet, The Helicoidal Classification of Elements, Chemical News, 138, 372—374, 388—393, 1929.78. On the subject of beauty and elegance, there are now a number of thtee-dimen-... 

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