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A168208 Irregular table of the number of electrons of the n-th element of the PSE in atomic shells, read by rows.

%I A168208 #22 Jun 02 2019 09:19:06
%S A168208 1,2,2,1,2,2,2,3,2,4,2,5,2,6,2,7,2,8,2,8,1,2,8,2,2,8,3,2,8,4,2,8,5,2,
%T A168208 8,6,2,8,7,2,8,8,2,8,8,1,2,8,8,2,2,8,9,2,2,8,10,2,2,8,11,2,2,8,13,1,2,
%U A168208 8,13,2,2,8,14,2,2,8,15,2,2,8,16,2,2,8,18,1,2,8,18,2,2,8,18,3,2,8,18,4,2
%N A168208 Irregular table of the number of electrons of the n-th element of the PSE in atomic shells, read by rows.
%C A168208 For the n-th element in the periodic system of elements, row n of the table shows the occupancy of the K-shell, then the L-shell, then the M-shell etc.
%C A168208 Row sums are A000027(n). A093907(c) is the maximum number that may appear in column c.
%C A168208 How are rows defined when the n-th element has more than one possible electron configuration? For example, element no. 28 (Nickel) has two electron configurations, namely 2, 8, 16, 2 and 2, 8, 17, 1, and it is disputed which of them is the ground state configuration of Nickel. - _Felix Fröhlich_, Jun 02 2019
%H A168208 Wikipedia, <a href="https://en.wikipedia.org/wiki/Electron_configurations_of_the_elements_(data_page)">Electron configurations of the elements (data page)</a>
%e A168208 From _Felix Fröhlich_, Jun 02 2019: (Start)
%e A168208 Irregular table starts as follows, where Z denotes the atomic number:
%e A168208   Z  | Element name | Electrons per shell
%e A168208   -----------------------------------------
%e A168208    1 | Hydrogen     | 1
%e A168208    2 | Helium       | 2
%e A168208    3 | Lithium      | 2, 1
%e A168208    4 | Beryllium    | 2, 2
%e A168208    5 | Boron        | 2, 3
%e A168208    6 | Carbon       | 2, 4
%e A168208    7 | Nitrogen     | 2, 5
%e A168208    8 | Oxygen       | 2, 6
%e A168208    9 | Fluorine     | 2, 7
%e A168208   10 | Neon         | 2, 8
%e A168208   11 | Sodium       | 2, 8,  1
%e A168208   12 | Magnesium    | 2, 8,  2
%e A168208   13 | Aluminium    | 2, 8,  3
%e A168208   14 | Silicon      | 2, 8,  4
%e A168208   15 | Phosphorus   | 2, 8,  5
%e A168208   16 | Sulfur       | 2, 8,  6
%e A168208   17 | Chlorine     | 2, 8,  7
%e A168208   18 | Argon        | 2, 8,  8
%e A168208   19 | Potassium    | 2, 8,  8, 1
%e A168208   20 | Calcium      | 2, 8,  8, 2
%e A168208   21 | Scandium     | 2, 8,  9, 2
%e A168208   22 | Titanium     | 2, 8, 10, 2
%e A168208   23 | Vanadium     | 2, 8, 11, 2
%e A168208   24 | Chromium     | 2, 8, 13, 1
%e A168208   25 | Manganese    | 2, 8, 13, 2
%e A168208   26 | Iron         | 2, 8, 14, 2
%e A168208   27 | Cobalt       | 2, 8, 15, 2
%e A168208 (End)
%Y A168208 Cf. A173642.
%K A168208 nonn,less,tabf
%O A168208 1,2
%A A168208 _Paul Curtz_, Nov 20 2009
%E A168208 Redefined as an irregular table by _R. J. Mathar_, Dec 05 2009
%E A168208 Edited by _Felix Fröhlich_, Jun 02 2019