7 8 
THE QUANTUM 
[v. 4 
Arrangement of Electrons in Rare Gases 
(Main Smith and Stoner) 
Atomic 
number 
K 
Hi 
L 
2 u 2 21 2 22 
M 
3ll 321 322 332 3s3 
N 
4ll 421 422--- 
He 
2 
2 
Ne 
IO 
2 
224 
A 
18 
2 
224 
2 2 4 
Kr 
36 
2 
224 
22446 
224 
nie 
ii 
2 1 2 2 
3l 32 33 
4i 42 
In the light of Stoner’s scheme of electron distribution, 
Sommerfeld has recently given the following table to show the 
classification of X-ray levels : 
K 
Li 
Ln 
Liu 
M x 
M„ 
M m 
M IV 
M v 
K 
L n 
L 2 i 
L 2 2 
M u 
M 21 
M 22 
M 32 
M33 
IS 
2S 
2pi 
2^2 
35 
3Pi 
3p2 
3^2 
3^3 
2 
2 
2 
4 
2 
2 
4 
4 
6 
Nx 
N n 
N ni 
Niv 
N v 
Nvi 
Nyii 
N n 
N„ 
n 22 
N32 
N33 
N 43 
N44 
4 s 
aPi 
4P* 
4^2 
4^3 
4/s 
4 A 
2 
2 
4 
4 
6 
6 
8 
In the first line of the table is given the designation of the levels 
according to Bohr and Coster ; in the second line the nomenclature 
adopted by Sommerfeld in the new edition of his book, the double 
suffixes corresponding to the k and j of Landé ; the third line 
shows the correspondence throughout with the doublet character 
of the alkalies, the subscript index giving the inner quantum 
number j ; the last line gives the quantum weights of the respec 
tive terms as 2j, which, according to Stoner, is equal to the 
number of electrons in the completed X-ray sub-groups. 
4. Complex Spectra and their Interpretation 
A great advance in our knowledge of atomic states and spectral 
terms has been brought about by the important researches of