April 28, 1922] 



SCIENCE 



459 



The balance of advantages seems to lie with 

 the selection of either Esperanto or Ido or some 

 modification of them recommended by experts 

 on language. The vital requirement is that the 

 auxiliary language should be kept auxiliary, 

 the vehicle of formal statement. If it should 

 become a language of common speech, of emo- 

 tion, or of literature it will at once fail of its 

 purpose and be only an additional linguistic 

 burden. — London Times. 



SPECIAL ARTICLES 



ATOMIC STRUCTURE 

 There has been considei-able discussion in 

 the literature, during the past few montlis, of 

 the Lewis theory of atomic structure^ and 

 Ijangmuir's extension of it to the heavy ele- 

 ments.- In 1919 and 1920 the writer worked 

 out a somewhat different extension of this 

 theory. For various reasons its publication has 

 been delayed, but in a few months a paper 

 describing it in some detail is to appear. Be- 

 cause of this delay, a short outline of the 

 theory may not be out of place here. 



The number of electrons in each shell of the 

 lighter atoms is the same as in the original 

 Lewis theory. It is assumed, however, that 

 the fifth, sixth, seventh and eighth electrons in 

 the second and third shells pair off with the 

 first four, the distance between the electrons in 

 each of these paii's, and also in each pair 

 formed by bonding between atoms, being much 

 less than the distance between pairs. These 

 shells are therefore tetrahedra of pairs instead 

 of cubes of single electrons.^ The electrons in 

 each shell (after the second) tend to be placed 

 opposite the centers of the faces of the imag- 

 inary polyhedron formed by the electron 

 groups in the underlying shell. If a certain 

 shell is a tetrahedron, the next shell out will 

 also be a tetrahedron; if the inner shell is a 

 cube, the outer shell will be an octahedron (six 

 points, eight faces); and if the smaller shell is 

 an octahedron, it will be surrounded by a tetra- 

 hedron — four of its eight faces then being 

 occupied — or by a cube. 



ij. Am. Chcjn. Soc, 38: 762 (1916). 



^-Ihid., 41: 868 (1919). 



3 Cf. Lewis, loc. cit., p. 779. 



When the nuclear charge becomes sufficiently 

 great, the same forces which cause pairing of 

 electrons in nitrogen result in the formation of 

 triplets in the inner shells of the heavier 

 atoms. The type of force between electrons 

 necessary to account for these phenomena is 

 discussed in my longer paper and will not be 

 considered here. As one after another of the 

 outer electrons are drawn into an inner shell to 

 form triplets, the remaining pairs are i)ushed 

 further and further from the nucleus. This 

 may result in rearrangement of the kernel 

 structure, as indicated in the examples of 

 atomic structure given below. Often, in dif- 

 ferent environments, different kernel structures 

 are stable, some having more valence electrons 

 and fewer triplets than others, etc. 



The structures resulting from the applica- 

 tion of the foregoing ideas I shall represent by 

 means of formuliE, in which the first paren- 

 thesis represents the nucleus and indicates its 

 charge, the remaining parentheses each repre- 

 senting a shell of electrons, in order from the 

 nucleus out. The number of electron-groups 

 and the number of electrons in each group are 

 indicated for every shell, except (in some 

 cases) the valence shell. Formute for atoms 

 and ions of some of the elements follow : 



H ( +1)(1) 



He ( .+.2) (2x1) 



C ( -fG)(2xl)(4) 



A^e (+10;(2xl)(4.x2) 



CI- [(+17) (2x1) (4x2) (4x2)]- or 



[(+17) (2x1) (8x2)]- 

 A (+18)(2.xl)(4x2)(4x2)oi- 



(+18) (2x1) (8x2) 

 Co-* [ (+27) (2x1) (6x 3+ 2x2)]-* 

 Cu++ [(+29) (2x1) (5x3 + 1x2) (4x2)]-^+ 

 Cu* [(+29)(2xl)(6x3)(4x2)] + 

 Zn- [ (+30) (2x1) (6x3) (4x2)]- 

 Br- [(+35) (2x1) (6x3) (8x2)]- 

 Kr (+36) (2x1) (6x3) (8x2) 



Ag* [ (+47) (2.xl) (8x3) (6x2) (4x2)] + 

 Su (+50) (ixl) (8x3) (6x2) (4x2) (4) and 



(+50) (2x1) (6x3) (8x2) (6x2) (2) 

 I- [(+53) (2x1) (8x3) (6x2) (S.-c2)]- 

 Xe (+54) (2x1) (8x3) (6x2) (8x2) 

 Ce (+58) (2x1) (8x3) (6x2) (8x2) (4) and 



(+58) (2x1) (8x3) (1x3 + 5x2) (8x2) (3) 

 Lu (+71) (2x1) (8x3) (6x3) (8x3) (3) 

 Ta (+73) (2x1) (8x3) (6x3) (8x3) (5) 

 Au-i- [(+79) (2x1) (8x3) (6.x3) (8x2) (6x3)] + 



