Tables 603 (b) (continued) aqc. 



TABLE 603(B) (continued).— Atomic Structure, Bohr Atom 



correction to the mass is necessary. Their quantization brought another quantum number ; 

 the so-called total quantum number, n, now becomes the sum of two since both the radii 

 (r) and azimuth (<p) of the electron vary. The orbit is usually designated by two quantum 

 numbers, the total, n, and the azimuthal (0) viz: i.i, 2.3 (p orbit, circular), 2.1 (s orbit, 



elliptical), 3.3, 3.2, 3.1 The following figure illustrates the first four sets of orbits 



of the hydrogen atom. The table indicates the modes of the quantum numbers (02 radius 

 inner orbit, a, b, varying). 



nk 

 i.i 

 2.1 

 2.2 

 3-1 

 3-2 

 3-3 



i.i orbit to — > 

 Volts observed 

 \ Lyman series, fi 

 " Balmer 2.2 orbit 

 " Paschen 3.3 orbit 

 " Brackett 4.4 orbit 



total 



radial 



2.2 

 10.15 

 .I2l6 



3-3 

 12.05 

 .1026 

 .6563 



The remarkable prediction and consequent observation of the " fine-structure of spec- 

 trum lines resulted from this postulate." Thus all the lines of the Balmer series, con- 

 sisting of jumps into the state of total quantum 2, possessing 2 orbits, a circle and an 

 ellipse, should show a fine structure due to energy differences of these circular and 

 elliptical orbits. Approximately they should be all doublet lines of wave length predictable 

 from laws of orbital mechanics. The separations should be .365 cm" 1 ; actually .36 cm" 1 

 (Houston) was found. The separation should vary as the 4th power atomic no. Paschen 

 (1916) actually found for He +, 16 X .365 cm" 1 . Further remarkable results came from 

 Epstein's (Ann. Phys., 50, 489, 1916) work on the Stark effect and 4 the prediction of the 

 separation of the so-called L doublets of X-ray spectra. If actually a relativity doublet, 

 one must multiply the H separation by 71 millions (92 4 ) ; also checked with experiment. 



Inner quantum numbers. 1 — It became necessary (1920, Sommerfeld, Ann. Phys., 63, 

 221, 1920) to account for further fine structure, e. g. : In X rays the L orbits or levels 

 correspond to n = 2, permitting only two different orbits, 2.2 (circle) and 2.1 (ellipse) : 

 but lines of 3 close wave lengths were observed — two being the regular expected doubtlet 

 whose frequency varies with 2* as expected. These two levels are indicated by the two 

 diverging lines, L2, L 3 in the following figure. 



1 Millikan, Proc. Amer. Philos. Soc, 66, 211, 1927, from which much of the accompany- 

 ing description is condensed. 



Smithsonian Tables 



