The best Aufbau mnemonic: The periodic table - ACS Publications

Using the periodic table exclusively to rationalize electron assignments has the advantage of emphasizing the experimental aspect of the science and a...
0 downloads 0 Views 1MB Size
They appear in all the schools in which I substitute and are mentioned by teachers in informal discussions a t teaching conventions. Inner city teachers have even more problems with this than those of us teaching in urban areas. The solutions to this problem are simple. Take all the money that is being spent on commissions to study education and spend it for developing classes for teachers to improve themselves. A good chemistry teacher does not need physical chemistry with calculus, the teacher needs physical chemistry taught with understanding. This teacher needs to know how chemistry is used in industry and to know why a particular concept is important to the life of the student. Remind all the people who are critical of today's teacher that the school of today is responsible for more than teaching the 3R's. Start teaching your children to be responsible for their actions and demand that others do the same. If your children forget their lunch money or homework, do you bail them out and bring it in or do they suffer the consequences of their lack of responsibility? When that big paper is due and your child's paper isn't ready, do you write an excuse saying they are sick? Are you teaching your child honesty and responsibility? Don't be critical of the graduate from the school if you do not help educate that graduate in the skills needed to k e e a~ "iob. Demand that school administrators enforce the school rules and that there be disci~linein classes. The disru~tive students deny other students an educational opportunity. The school population containing 33% minority children and 25% poor children will not be a problem for the schools if people will stop making excuses for these children and their parents. The minority and poor children children can achieve if they will. This has been demonstrated in many schools. If children do not desire an education, educational research demonstrates that thev will not receive it. even with the best instruction in the world. If you really believe that there will be a demand for all these technically literate people when they graduate then don't wait for the schools to solve the problem. They can't! They need the support of the public and they need a change in public attitude. The schools will only succeed when the public is ready to take responsibility for education and is willing to work in support of education instead of waiting for the schools to do it all. My wife is an outstanding teacher and has a few awards supporting this claim. The lack of public support and encouragement has her counting the yean until she can retire. I was a good high school teacher, although not outstanding. I retired as soon as I could, frustrated by the lack of encouragement and by the negative press caused by peoole who do not understand the nroblem. Teach for a vear in the public schools if you can. If you still think the schools are the problem, fine! More likely, you will wonder how schools turn out as many good students as they do with the quality of the students entering the schools.

Alternative Aufbau Mnemonics To the Editor:

It is interesting to see, as Scerri ( I ) points out, the pastime of devising Aufabu mnemonics to teach electronic configurations still continues. Scerri cites several recent examples. However, almost thirty years ago, Andrews & Kokes (2-4)offered a method for determining electronic configurations which we believe to be one of the best presentations. Our discussion of their method and our expanded uses of it have been described elsewhere (5). Joseph P. Bevak Eugene J. McDevitt Siena College Loudonville, NY 12211 Literature Cited 1. Scerri, E.R. J. C k m . Edue. 1891.6S.445 2. Andrews, D. H.; K0kes.R. J.Fundomentol Chemistry; Wiley: New York, 1962;ppl05. 510-13, and inslde back cover 3. Andrewa, D. H.;Kokea,R. J.Fun&montd Ckrnistry, 2nd dd.; Wiley:NeuYork, 1965: pp 54,502406,and inside back ewer 4. Andrews, D. H.6fmducloryPhy~LmlChernlsfry;Mffiraw-Hill: NewYorh 1970:pp. 2,n-n3 ", W".

5. Beuak, J . P.;MeDevitZ E. J. JColl. Sci k c h . 198?,16,43P36.

The Best Aufbau Mnemonic: The Periodic Table

&

A~

~

James T. Martino 471 3 BOOlh Road Oxforo.Oh 45056

430

Journal of Chemical Education

Dear Editor:

I was happy to see the letter by Scerri in the May 1991 issue of this Journal emphasizing the artificiality of mnemonics for fillinn electron confimrations. Every year I ask my freshmen if they have heard about orbitals. and thev alwavs tell me that thev have some artificial s&eme fo; memorizing(!) the order of filling of the orbitals as if the periodic table depended on these mnemonics. They have things exactly backwards! I should like to suneest that there is alreadv (or there the wall of every che&stry classshould be) hanging room a mnemonic device for eenerating the order of filling of the orbitals in the ~ufbau-approximation. This dev& the Denodic table itself. should be the only scheme used to talk about Aufbau. he closer we stay to the table, the closer we are to real chemistry. The reason that the 4s level fills before the 3d level is because potassium is similar to sodium, and does not have an entirely new chemistry-as does scandium. This kind of reasoning seems much closer to the real world than does some "n + 1rule" which talks about numerology and not chemistry. Exceptions to the straightforward trends, like chromium, are handled by pointing out that we should marvel that the Aufbau works as well as it does, not that it sometimes disagrees with what Nature has decided to do. I t is good, of course, to let students know that we are not teaching a "closed book" but rather a living subject about which not everything is known. Using the periodic table exclusively to rationalize elmtron assignments has the advantage of emphasizing the experimental aspect of the science and avoids giving the impression that chemistry is nothing but a set of mysterious rules. Oliver G. Ludwig Villanova University Villanova. PA 19085