author that this device provides the most simple and elegant method for memorizing the aufbau principle of the periodic system. We want to point out, however, that this idea is not new. To our knowledge F. Seel (1, 2) was the first who proposed it. In Seel's chessboard, which is shown below, the squares are marked in such a way that the system can be read from left to rieht and from too to bottom like a written text. The light line parallel to the'diagonal marks the beginning and the end of the oeriods. which alwavs start with an element with a single s-electron and (except for the first one) are terminated by an element with a fully occupied p-subshell.
Recommended Formal for the Periodlc Table To the Editor:
I wish to comment upon Loening's article "Recommended Format for the Periodic Table of the Elements" [1984, 61, 1361. The recommended format suffers from the followine drawbacks. (1) Useof letters 3d, 4d,. . . ,12dfar groupsof d hloek and numerals 1,2,. . . ,13,14, etc. for s andp blockgroups createsconfusion in the minds of students. Why have the letters s and P not been used for the s and p hloek ~"hgroups?Moreover, such a nomenclature cannot be correlated with the electronic configurationof an element in termsof s, p, d, f orbitals,whichiscertainlya basis of classification of elements in the four blocks in this long form of the periodic table. As for example Cr (Z = 24) has its ground state configuration 3d",4s1but ;L is a member of the 6d group in this format. On the other hand if one considers the case of Ne(Z = 10)with electronic configuration 2s2p6,it Seems very funny to say that it belongs to the 18th group. What purpose is served by delinking electronic structure of an element and its position in the periodic table in this way, is beyond understanding at least far a undergraduate student of chemistry. (2) The practice to call lanthanides as 4f and actinides as 5f elements is well-established. Now, if according,tothis new format all inner transition elements are called 3f elements, it will unnecessarily create confusion. The symbol 3f in itself is very muchconfusingas there is nosuchorhital. Moreover, then it will not he possible to distinguish lanthanides from actinides in terms of their positions in the periodic table. (3) In this format periods are also not numbered, which is also not justified.
Hy additiw 1,f rilws and cuiumni, this scheme also can be used todern~mstrarrthr theoretical expansim of the periodic svstem. w h e n writing ground state electron configurations, the known exceptions and special cases must he considered. Lrleralure Cited I . S e l , F. Addder Wirsen. 19fi9.6.44. 2. Seel, F. l'hrrnir h#r Lob. und R r t . 1981.12, 152,
Manfred Adelhelm Ernst-Gerhard Hbhn Padagogische Hachschule 7140 Ludwigsbwg Fed. Rep. Germany
Criticize wllh Care! To the Editor:
A new format was proposed by me a t the 7th ICCE a t Montpellier (France) in August, 1983. I think it should be considered as one of the several alternatives. R. C. Sharma Government College Kata (Rap) India
"Aufbau on a Chessboard" First Proposed by Seel To the Editor:
.
In the recent article "Aufbauon a Chessboard". 11986.63. . 607) Allan K. Hovland compares different mnemonics for writine" eround state electron confieurations for the ele" " ments. He recommends for this purpose the use of a chessboard as a method most convenient for students. From our teaching experience, we fully agree with the
1114
Journal of Chemical Education
I noted in "Simple Method for Determination of Oxidation Numbers of Atoms in Compounds" [1986,63,474] by Joel M. Kauffman a clearly and grossly incorrect statement about a paper that VanderWerf and I wrote [1980,57,42]. Kauffman states that "Sisler and VanderWerf discussed redox reactions in an effort to dispel chemical sophistry, hut they produced some of their own. . . in saying that an oxidation number of 4+ for the carbon atom in carbon dioxide requires the ~ostulationof a C4+ion." Aooarentlv Kauffman .. has not read (at least not carefully) our paper to which he refers for that paper contains no such statement. We stated that "the assu&kion that carbon has lost four electrons in its oxidation to carbon dioxide requires the postulation of the existence of carbon in carhon dioxide as the C" ion." This is a much different statement from the one that Kauffman so carelessly and incorrectly attributes to us. Before an author attributes an adverse quality to another author's writing, he should, a t the very least, carefully read the paper that he is criticizing. Harry H. Sisler University of Florida Gainesville. FL 32611
