LETTERS Mythology and Elemental Etymology: The Names of Elements 92 through 94
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To the Editor: The origin of the names of the elements by D. W. Ball [1985, 62, 7871 and by Christopher Glidewell [1986, 63(8), 6591 are very interesting, and this fits in very well with respect to how the names of the elements are obtained that is discussed in the first round of general chemistry. The elements are named for various contributors of physical science and for various places (cities, continents, countries, and states) on earth. The names also are based on some physical or chemical property about that element as in the case of bromine. Radioactivity and related topics are covered in the second round of general chemistry, qualitative analysis, and physical chemistry. This includes the mass-energy relation and the particles and the elements in reactions 1 and 2 were taken to be the beta positron instead of the beta electron until it was found out that the reactions were well established. If 0 had been the beta positron, ;:'Pa andg9Th would have been obtained in (1) and U ;:' would have been obtained a t the end of (2). E = mc2 is the mass energy relation, and it is used to calculate the energy for all nuclear reactions inclusive of (1) and (2). When rn is replaced by Am, i t is the mass defect, the difference between the sum of the masses of the products and the sum of the masses of the reactants. If rn is positive, the reaction is endoergic and if rn is negative, the reaction is exoergic. $i9This thorium-239 and i;9Pa is protactinium-239. Thorium was named in honor of Thor or Mars, the god of thunder or war. Protactinium formally was named protoactinium. The current name is the result of a name shortening.
--
id. 2") 2 3 8 ~ 92
+ :H
; ; 3 ~ ~
2$
(3)
+ ;;'Np
(4)
An even briefer shorthand is ;i8U (d, 2,) ;i8Np. In suggesting the interchange of d and 2n, Hill is being somewhat fanciful: (2n, d) reactions are unimportant in ii8U, whose major reaction with neutrons is neutron capture, (n, y) reaction, followed by @ decay. The captures may he single (eq. 5) or multiple (eqs. 6,7):
The processes described in eqs 6 and 7 represent (5)the first terrestrial syntheses of elements 99 and 100. With fast neutrons ZU ;' undergoes an (n, 2n) reaction (eq 8), providing another synthesis of neptunium from uranium (6):
~ h e n G ? ' ~ howsoever a, formed, undergoes &decay the product is ;;SU, not iisTh as Hill asserts. Indeed the isotopes g8Th and i 9 T h mentioned by Hill appear to be unknown (7). Christopher Glidewell University of St. Andrews St. Andrews, Fife KY16 9ST Scotland. UK
Literature Clted 1. Be1l.D. W. J. Chem.Educ. 1985,62,787. 2. Sesborg. G. T. Man-Mode Tronsurcniurn Elements: Prentice-Hall: Englewaad Cliffs, h,,
70-3
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William D. Hill, Jr. N. C. Cenhal University Durham. NC 27707
To the Editor:
The A.C. Approach to Liquid Spill Clean Up
Although the note [1986,63,659] on elements 92 through 94 and the full article by Ball (I) which led to it were concerned primarily with the origins of the names of chemical elements, Hill's comments are directed mainly toward the nuclear chemical equations describing the transformations of ;;'U. Hill appears to have misunderstood some of the normal conventions used (2, 3) in such equations; thus, he risks confusion. The symbol P above a reaction arrow signified @-decay,in which the electron is not a reactant, as in a normal chemical equation, but a byproduct (4). Thus eq 1is a shorthand form of eq 2:
-
B
3 l - z9Np (1) (2) :!% :%'Np + O_,e The symbol 0 is a conventional symbol for loss of Ole, although 6- is sometimes used (2,3): for loss of!,e, the symbol @+ is employed (3). Hence Hill's comment "no doubt fl is the beta positron" is entirely incorrect, and the deductions following are equally so. The symbol (d, 2n) above a reaction arrow (eq 3) is a shorthand representation of eq. 4: 652
3. Choppin. G. R.,Rydbrg. J. Nuclear Chemiafry: Pergsmon: Oxford. 19M. 4. Ref. 4, Chapter 11. 5. Ref. 3.00 23. 21.77. 8 Ref 4. p-504. 7 Ref. 4. Appendix N
Journal of Chemical Education
To the Editor: With reference to Nelson's valuable article [1986, 63, A.1671 on dealing withchemicalspills, i t has beenour experience that diatomaceous earth (kept in laboratories as a filter aid) is a most effective absorbent for spills of both organic and inorganic liquids. When worked into any spill a sticky powder results which may be gathered up with a dust pan and nylon bristle brush. The affected surface is sufficiently clean to be mopped with soap and water, while the spent nowder mav be treated anoro~riatelvwhen convenient. Filter aid was chosen be'caise of iis high absorption characteristics alone with relative cheanness and readv availability in the laboratory stores. containers of diatomaceous earth were sited throughout the working areas along with other safety equipment. John Runcle Site Chemical Stores The Wellcome Research Laboratories Lande" court ~;ckenham BR3 3BS England
