letters The Nonexistence of NH40H To the Editor:
T. R. Tuttle, Jr.'s assertion [1991, 68, 533, in defense of "NH40H"l,uncontested in the accompanying letters, that "thermodynamic stability ... forms the proper basis for deciding whether a chemical compound exists" denies the existence of the organic compounds in his own neurons. Ronald L. Rlch 112 S. Spring St. Bluffton. OH 45817-1112
To the Editor:
Perhaps my language in support of the existence of NHaOH was insufficiently precise to encompass all possible conditions for "existence" in that my reference to the proper basis could better be expressed as a proper basis. Nevertheless, this putative imprecision on my part in no way weakens the argument in support of the existence of ammonium hydroxide. Its thermodynamic stability is surely sufficient to ensure its existence even though it may not be necessary. Thomas R. Tuttle, Jr. Brandeis University Waltharn, MA 02254-9110
perfect way of answering a student's question on how an electron gets across a node." I have found that the question of how an electron gets across a node, for example in a pi bond, is one generally asked by a beginner who could not comprehend any answer naturally arising from the current theories presented by Nelson. At this level, I find that students need some visual model to help them remember that there are two halves to the orbital and nothing much in between-so that thev can use that information for more imoortant things s&h as learning how akenes read with s m h molecules. For this purpose, I have suggested that a pi bond is a description of the space a n electron pair generally occupies and that the descriotion is based on reactions. e x ~ e r i mentation and mathemitical calculation. As a des'cription of space wherein the electrons might be found, we are not concerned with how but what. I remind them that a description is what we use for visualization to make other more important information easier to understand and suggest, finally, that one accepts the pi bond just a s one accepts the hot dog bun-there are two halves to it and just as one does not have a complete hot dog bun when one has only the top or bottom half, one does not have a complete pi bond when one pictures only the top or bottom half. And who would ask the question "how does the bread in the hot dog bun get from one half to the other?" Aline M. (Lindy)Harrison York College of Pennsylvania York, PA 17405
A Mole Balance To the Editor
Our new Mettler PM-460 Balances have the capability to count pieces. To use this feature you need to place on the pan 10 pieces of the material of interest. Since one millimole of aluminum weighs 0.0270 g, I used a sample weighing 0.270 g to represent the 10 pieces (millimoles). After that the balance reads out directly in pieces or in this case the millimoles of aluminum. With a used beverage can, it read 614 pieces or 614 mmol. The balance readily allows one to jump back to grams and for my can it showed 16.580 g (an improvement in significant figures). The capacity of this balance is 410 g or about 15,000 mmol of aluminum. In order to measure out millimoles of other materials, all one would have to do is to have a series of weights wrresponding to 10 mmol of each material for the calibration steo. I haven't decided vet how to include this into our laboratory experiments-any ideas? Maybe the balance makers will somedav include the built-in reference weights and we can more easily measure out our chemicals dGectly in millimoles. Ravmond A. Sommers ~nigersity01 Wisconsin Stevens Point WI 54481 The Interpretation of Quantum Theory to Beginners To the Editor:
I read with great interest the article by P. G. Nelson "How Do Electrons Get Across Nodes" [J. Chem. Educ. 1988,67,6431. I t describes, with considerable acuity, a bit of each of the current theories of electron location and, in each case, points out the major difficulty with that solution to the electron's location a t any point in time. It concludes with the statement that "there is a t the present time no 260
Journal of Chemical Education
Naming the Big Ones To the Editor:
In your August 1991 Letters, Joseph Senccn invites readers to respond to his suggestions for the nomenclature of elements 104 and beyond: The issue of naming elements 104 and 105 has fairly well been settled ( c.f, The Elements Beyond Uranium, by G. T. Seaborg and W. D. Loveland).The nuclear chemistry community is already using Rutherfordium (Rf) for element 104 and Hahnium (Ha) for element 105. The rest of the chemistry community should be doing the same. As far as the unnamed elements beyond 105, I would prefer that they be named after prominent chemists. I have two reasons: (1)surely we have not run out of prominent chemists deserving rewgnition; (2) it gives me additional opportunity as a teacher to include historical topics (students rightly assume if someone has had a n element named after him that he must be someone worth knowing about). In regards to the issue of priority of discovery of elements and who has the right to name new elements, perhaps the current system of the discoverer having the right to name the element could be reolaced with a lottew svstem. The various laboratones a r o h d the world elaim"ing priority of discoverv for elements 106-110 could suhmlt w the IUPAC two to ihhree choices of names. The IUPAC would then draw names at random. If more than five names are submitted, the remaining names could be "pre-assigned"to elements 111, etc., when they are discovered. Brian H. Nordstrom Ernbry-Riddle Aeronautical University Prescon, AZ 86301
