Electron configurations of the elements (data page)

This page shows the electron configurations of the neutral gaseous atoms in their ground states. For each atom the subshells are given first in concise form, then with all subshells written out, followed by the number of electrons per shell. For phosphorus (element 15) as an example, the concise form is [Ne] 3s² 3p³. Here [Ne] refers to the core electrons which are the same as for the element neon (Ne), the last noble gas before phosphorus in the periodic table. The valence electrons (here 3s² 3p³) are written explicitly for all atoms.

Electron configurations of elements beyond hassium (element 108) have never been measured; predictions are used below.

As an approximate rule, electron configurations are given by the Aufbau principle and the Madelung rule. However there are numerous exceptions; for example the lightest exception is chromium, which would be predicted to have the configuration 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁴ 4s², written as [Ar] 3d⁴ 4s², but whose actual configuration given in the table below is [Ar] 3d⁵ 4s¹.

Note that these electron configurations are given for neutral atoms in the gas phase, which are not the same as the electron configurations for the same atoms in chemical environments. In many cases, multiple configurations are within a small range of energies and the irregularities shown below do not necessarily have a clear relation to chemical behaviour.^[1] For the undiscovered eighth-row elements, mixing of configurations is expected to be very important, and sometimes the result can no longer be well-described by a single configuration.^[2]

Legend
1s	2s	2p	3s	3p	3d	4s	4p	4d	4f	5s	5p	5d	5f	6s	6p	6d	7s	7p
1 H hydrogen : 1s¹
1s¹
1
2 He helium : 1s²
1s²
2
3 Li lithium : [He] 2s¹
1s²	2s¹
2	1
4 Be beryllium : [He] 2s²
1s²	2s²
2	2
5 B boron : [He] 2s² 2p¹
1s²	2s²	2p¹
2	3
6 C carbon : [He] 2s² 2p²
1s²	2s²	2p²
2	4
7 N nitrogen : [He] 2s² 2p³
1s²	2s²	2p³
2	5
8 O oxygen : [He] 2s² 2p⁴
1s²	2s²	2p⁴
2	6
9 F fluorine : [He] 2s² 2p⁵
1s²	2s²	2p⁵
2	7
10 Ne neon : [He] 2s² 2p⁶
1s²	2s²	2p⁶
2	8
11 Na sodium : [Ne] 3s¹
1s²	2s²	2p⁶	3s¹
2	8		1
12 Mg magnesium : [Ne] 3s²
1s²	2s²	2p⁶	3s²
2	8		2
13 Al aluminium : [Ne] 3s² 3p¹
1s²	2s²	2p⁶	3s²	3p¹
2	8		3
14 Si silicon : [Ne] 3s² 3p²
1s²	2s²	2p⁶	3s²	3p²
2	8		4
15 P phosphorus : [Ne] 3s² 3p³
1s²	2s²	2p⁶	3s²	3p³
2	8		5
16 S sulfur : [Ne] 3s² 3p⁴
1s²	2s²	2p⁶	3s²	3p⁴
2	8		6
17 Cl chlorine : [Ne] 3s² 3p⁵
1s²	2s²	2p⁶	3s²	3p⁵
2	8		7
18 Ar argon : [Ne] 3s² 3p⁶
1s²	2s²	2p⁶	3s²	3p⁶
2	8		8
19 K potassium : [Ar] 4s¹
1s²	2s²	2p⁶	3s²	3p⁶		4s¹
2	8		8			1
20 Ca calcium : [Ar] 4s²
1s²	2s²	2p⁶	3s²	3p⁶		4s²
2	8		8			2
21 Sc scandium : [Ar] 3d¹ 4s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹	4s²
2	8		9			2
22 Ti titanium : [Ar] 3d² 4s²
1s²	2s²	2p⁶	3s²	3p⁶	3d²	4s²
2	8		10			2
23 V vanadium : [Ar] 3d³ 4s²
1s²	2s²	2p⁶	3s²	3p⁶	3d³	4s²
2	8		11			2
24 Cr chromium : [Ar] 3d⁵ 4s¹
1s²	2s²	2p⁶	3s²	3p⁶	3d⁵	4s¹
2	8		13			1
25 Mn manganese : [Ar] 3d⁵ 4s²
1s²	2s²	2p⁶	3s²	3p⁶	3d⁵	4s²
2	8		13			2
26 Fe iron : [Ar] 3d⁶ 4s²
1s²	2s²	2p⁶	3s²	3p⁶	3d⁶	4s²
2	8		14			2
27 Co cobalt : [Ar] 3d⁷ 4s²
1s²	2s²	2p⁶	3s²	3p⁶	3d⁷	4s²
2	8		15			2
28 Ni nickel : [Ar] 3d⁸ 4s²
1s²	2s²	2p⁶	3s²	3p⁶	3d⁸	4s²
2	8		16			2
29 Cu copper : [Ar] 3d¹⁰ 4s¹
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s¹
2	8		18			1
30 Zn zinc : [Ar] 3d¹⁰ 4s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²
2	8		18			2
31 Ga gallium : [Ar] 3d¹⁰ 4s² 4p¹
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p¹
2	8		18			3
32 Ge germanium : [Ar] 3d¹⁰ 4s² 4p²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p²
2	8		18			4
33 As arsenic : [Ar] 3d¹⁰ 4s² 4p³
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p³
2	8		18			5
34 Se selenium : [Ar] 3d¹⁰ 4s² 4p⁴
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁴
2	8		18			6
35 Br bromine : [Ar] 3d¹⁰ 4s² 4p⁵
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁵
2	8		18			7
36 Kr krypton : [Ar] 3d¹⁰ 4s² 4p⁶
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶
2	8		18			8
37 Rb rubidium : [Kr] 5s¹
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶			5s¹
2	8		18			8				1
38 Sr strontium : [Kr] 5s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶			5s²
2	8		18			8				2
39 Y yttrium : [Kr] 4d¹ 5s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹		5s²
2	8		18			9				2
40 Zr zirconium : [Kr] 4d² 5s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d²		5s²
2	8		18			10				2
41 Nb niobium : [Kr] 4d⁴ 5s¹
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d⁴		5s¹
2	8		18			12				1
42 Mo molybdenum : [Kr] 4d⁵ 5s¹
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d⁵		5s¹
2	8		18			13				1
43 Tc technetium : [Kr] 4d⁵ 5s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d⁵		5s²
2	8		18			13				2
44 Ru ruthenium : [Kr] 4d⁷ 5s¹
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d⁷		5s¹
2	8		18			15				1
45 Rh rhodium : [Kr] 4d⁸ 5s¹
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d⁸		5s¹
2	8		18			16				1
46 Pd palladium : [Kr] 4d¹⁰
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰
2	8		18			18
47 Ag silver : [Kr] 4d¹⁰ 5s¹
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰		5s¹
2	8		18			18				1
48 Cd cadmium : [Kr] 4d¹⁰ 5s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰		5s²
2	8		18			18				2
49 In indium : [Kr] 4d¹⁰ 5s² 5p¹
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰		5s²	5p¹
2	8		18			18				3
50 Sn tin : [Kr] 4d¹⁰ 5s² 5p²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰		5s²	5p²
2	8		18			18				4
51 Sb antimony : [Kr] 4d¹⁰ 5s² 5p³
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰		5s²	5p³
2	8		18			18				5
52 Te tellurium : [Kr] 4d¹⁰ 5s² 5p⁴
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰		5s²	5p⁴
2	8		18			18				6
53 I iodine : [Kr] 4d¹⁰ 5s² 5p⁵
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰		5s²	5p⁵
2	8		18			18				7
54 Xe xenon : [Kr] 4d¹⁰ 5s² 5p⁶
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰		5s²	5p⁶
2	8		18			18				8
55 Cs caesium : [Xe] 6s¹
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰		5s²	5p⁶			6s¹
2	8		18			18				8				1
56 Ba barium : [Xe] 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰		5s²	5p⁶			6s²
2	8		18			18				8				2
57 La lanthanum : [Xe] 5d¹ 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰		5s²	5p⁶	5d¹		6s²
2	8		18			18				9				2
58 Ce cerium : [Xe] 4f¹ 5d¹ 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹	5s²	5p⁶	5d¹		6s²
2	8		18			19				9				2
59 Pr praseodymium : [Xe] 4f³ 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f³	5s²	5p⁶			6s²
2	8		18			21				8				2
60 Nd neodymium : [Xe] 4f⁴ 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f⁴	5s²	5p⁶			6s²
2	8		18			22				8				2
61 Pm promethium : [Xe] 4f⁵ 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f⁵	5s²	5p⁶			6s²
2	8		18			23				8				2
62 Sm samarium : [Xe] 4f⁶ 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f⁶	5s²	5p⁶			6s²
2	8		18			24				8				2
63 Eu europium : [Xe] 4f⁷ 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f⁷	5s²	5p⁶			6s²
2	8		18			25				8				2
64 Gd gadolinium : [Xe] 4f⁷ 5d¹ 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f⁷	5s²	5p⁶	5d¹		6s²
2	8		18			25				9				2
65 Tb terbium : [Xe] 4f⁹ 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f⁹	5s²	5p⁶			6s²
2	8		18			27				8				2
66 Dy dysprosium : [Xe] 4f¹⁰ 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁰	5s²	5p⁶			6s²
2	8		18			28				8				2
67 Ho holmium : [Xe] 4f¹¹ 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹¹	5s²	5p⁶			6s²
2	8		18			29				8				2
68 Er erbium : [Xe] 4f¹² 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹²	5s²	5p⁶			6s²
2	8		18			30				8				2
69 Tm thulium : [Xe] 4f¹³ 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹³	5s²	5p⁶			6s²
2	8		18			31				8				2
70 Yb ytterbium : [Xe] 4f¹⁴ 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶			6s²
2	8		18			32				8				2
71 Lu lutetium : [Xe] 4f¹⁴ 5d¹ 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹		6s²
2	8		18			32				9				2
72 Hf hafnium : [Xe] 4f¹⁴ 5d² 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d²		6s²
2	8		18			32				10				2
73 Ta tantalum : [Xe] 4f¹⁴ 5d³ 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d³		6s²
2	8		18			32				11				2
74 W tungsten : [Xe] 4f¹⁴ 5d⁴ 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d⁴		6s²
2	8		18			32				12				2
75 Re rhenium : [Xe] 4f¹⁴ 5d⁵ 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d⁵		6s²
2	8		18			32				13				2
76 Os osmium : [Xe] 4f¹⁴ 5d⁶ 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d⁶		6s²
2	8		18			32				14				2
77 Ir iridium : [Xe] 4f¹⁴ 5d⁷ 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d⁷		6s²
2	8		18			32				15				2
78 Pt platinum : [Xe] 4f¹⁴ 5d⁹ 6s¹
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d⁹		6s¹
2	8		18			32				17				1
79 Au gold : [Xe] 4f¹⁴ 5d¹⁰ 6s¹
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰		6s¹
2	8		18			32				18				1
80 Hg mercury : [Xe] 4f¹⁴ 5d¹⁰ 6s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰		6s²
2	8		18			32				18				2
81 Tl thallium : [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p¹
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰		6s²	6p¹
2	8		18			32				18				3
82 Pb lead : [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰		6s²	6p²
2	8		18			32				18				4
83 Bi bismuth : [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p³
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰		6s²	6p³
2	8		18			32				18				5
84 Po polonium : [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁴
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰		6s²	6p⁴
2	8		18			32				18				6
85 At astatine : [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰		6s²	6p⁵
2	8		18			32				18				7
86 Rn radon : [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁶
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰		6s²	6p⁶
2	8		18			32				18				8
87 Fr francium : [Rn] 7s¹
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰		6s²	6p⁶		7s¹
2	8		18			32				18				8			1
88 Ra radium : [Rn] 7s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰		6s²	6p⁶		7s²
2	8		18			32				18				8			2
89 Ac actinium : [Rn] 6d¹ 7s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰		6s²	6p⁶	6d¹	7s²
2	8		18			32				18				9			2
90 Th thorium : [Rn] 6d² 7s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰		6s²	6p⁶	6d²	7s²
2	8		18			32				18				10			2
91 Pa protactinium : [Rn] 5f² 6d¹ 7s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f²	6s²	6p⁶	6d¹	7s²
2	8		18			32				20				9			2
92 U uranium : [Rn] 5f³ 6d¹ 7s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f³	6s²	6p⁶	6d¹	7s²
2	8		18			32				21				9			2
93 Np neptunium : [Rn] 5f⁴ 6d¹ 7s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f⁴	6s²	6p⁶	6d¹	7s²
2	8		18			32				22				9			2
94 Pu plutonium : [Rn] 5f⁶ 7s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f⁶	6s²	6p⁶		7s²
2	8		18			32				24				8			2
95 Am americium : [Rn] 5f⁷ 7s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f⁷	6s²	6p⁶		7s²
2	8		18			32				25				8			2
96 Cm curium : [Rn] 5f⁷ 6d¹ 7s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f⁷	6s²	6p⁶	6d¹	7s²
2	8		18			32				25				9			2
97 Bk berkelium : [Rn] 5f⁹ 7s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f⁹	6s²	6p⁶		7s²
2	8		18			32				27				8			2
98 Cf californium : [Rn] 5f¹⁰ 7s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f¹⁰	6s²	6p⁶		7s²
2	8		18			32				28				8			2
99 Es einsteinium : [Rn] 5f¹¹ 7s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f¹¹	6s²	6p⁶		7s²
2	8		18			32				29				8			2
100 Fm fermium : [Rn] 5f¹² 7s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f¹²	6s²	6p⁶		7s²
2	8		18			32				30				8			2
101 Md mendelevium : [Rn] 5f¹³ 7s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f¹³	6s²	6p⁶		7s²
2	8		18			32				31				8			2
102 No nobelium : [Rn] 5f¹⁴ 7s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f¹⁴	6s²	6p⁶		7s²
2	8		18			32				32				8			2
103 Lr lawrencium : [Rn] 5f¹⁴ 7s² 7p¹
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f¹⁴	6s²	6p⁶		7s²	7p¹
2	8		18			32				32				8			3
104 Rf rutherfordium : [Rn] 5f¹⁴ 6d² 7s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f¹⁴	6s²	6p⁶	6d²	7s²
2	8		18			32				32				10			2
105 Db dubnium : [Rn] 5f¹⁴ 6d³ 7s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f¹⁴	6s²	6p⁶	6d³	7s²
2	8		18			32				32				11			2
106 Sg seaborgium : [Rn] 5f¹⁴ 6d⁴ 7s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f¹⁴	6s²	6p⁶	6d⁴	7s²
2	8		18			32				32				12			2
107 Bh bohrium : [Rn] 5f¹⁴ 6d⁵ 7s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f¹⁴	6s²	6p⁶	6d⁵	7s²
2	8		18			32				32				13			2
108 Hs hassium : [Rn] 5f¹⁴ 6d⁶ 7s²
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f¹⁴	6s²	6p⁶	6d⁶	7s²
2	8		18			32				32				14			2
109 Mt meitnerium : [Rn] 5f¹⁴ 6d⁷ 7s² (predicted)
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f¹⁴	6s²	6p⁶	6d⁷	7s²
2	8		18			32				32				15			2
110 Ds darmstadtium : [Rn] 5f¹⁴ 6d⁸ 7s² (predicted)
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f¹⁴	6s²	6p⁶	6d⁸	7s²
2	8		18			32				32				16			2
111 Rg roentgenium : [Rn] 5f¹⁴ 6d⁹ 7s² (predicted)
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f¹⁴	6s²	6p⁶	6d⁹	7s²
2	8		18			32				32				17			2
112 Cn copernicium : [Rn] 5f¹⁴ 6d¹⁰ 7s² (predicted)
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f¹⁴	6s²	6p⁶	6d¹⁰	7s²
2	8		18			32				32				18			2
113 Nh nihonium : [Rn] 5f¹⁴ 6d¹⁰ 7s² 7p¹ (predicted)
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f¹⁴	6s²	6p⁶	6d¹⁰	7s²	7p¹
2	8		18			32				32				18			3
114 Fl flerovium : [Rn] 5f¹⁴ 6d¹⁰ 7s² 7p² (predicted)
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f¹⁴	6s²	6p⁶	6d¹⁰	7s²	7p²
2	8		18			32				32				18			4
115 Mc moscovium : [Rn] 5f¹⁴ 6d¹⁰ 7s² 7p³ (predicted)
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f¹⁴	6s²	6p⁶	6d¹⁰	7s²	7p³
2	8		18			32				32				18			5
116 Lv livermorium : [Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁴ (predicted)
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f¹⁴	6s²	6p⁶	6d¹⁰	7s²	7p⁴
2	8		18			32				32				18			6
117 Ts tennessine : [Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁵ (predicted)
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f¹⁴	6s²	6p⁶	6d¹⁰	7s²	7p⁵
2	8		18			32				32				18			7
118 Og oganesson : [Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁶ (predicted)
1s²	2s²	2p⁶	3s²	3p⁶	3d¹⁰	4s²	4p⁶	4d¹⁰	4f¹⁴	5s²	5p⁶	5d¹⁰	5f¹⁴	6s²	6p⁶	6d¹⁰	7s²	7p⁶
2	8		18			32				32				18			8

Group 18 element (noble gas), has a complete shell. Complete shells are referred to as "[Ar]" for argon etc.

References

^ Jørgensen, Christian K. (1988). "Influence of rare earths on chemical understanding and classification". Handbook on the Physics and Chemistry of Rare Earths. Vol. 11. pp. 197–292. doi:10.1016/S0168-1273(88)11007-6. ISBN 9780444870803.
^ Nefedov, V. I.; Trzhaskovskaya, M. B.; Yarzhemskii, V. G. (2006). "Electronic Configurations and the Periodic Table for Superheavy Elements" (PDF). Doklady Physical Chemistry. 408 (Part 2). Pleaides Publishing: 149–151. doi:10.1134/S0012501606060029. S2CID 95738861. Retrieved 25 September 2020. configuration interaction is crucial in more than 30% of cases since its consideration leads to another ground-state configuration.

All sources concur with the data above except in the instances listed separately:

NIST

http://physics.nist.gov/PhysRefData/IonEnergy/ionEnergy.html ; retrieved July 2005, (elements 1–104) based on:
- Atomic Spectroscopy, by W.C. Martin and W.L. Wiese in Atomic, Molecular, & Optical Physics Handbook, ed. by G.W.F. Drake (AIP, Woodbury, NY, 1996) Chapter 10, pp. 135–153.

This website is also cited in the CRC Handbook as source of Section 1, subsection Electron Configuration of Neutral Atoms in the Ground State.

91 Pa : [Rn] 5f²(³H₄) 6d 7s²
92 U : [Rn] 5f³(⁴I^o_9/2) 6d 7s²
93 Np : [Rn] 5f⁴(⁵I₄) 6d 7s²
103 Lr : [Rn] 5f¹⁴ 7s² 7p¹ question-marked
104 Rf : [Rn] 5f¹⁴ 6d² 7s² question-marked

CRC

David R. Lide (ed), CRC Handbook of Chemistry and Physics, 84th Edition, online version. CRC Press. Boca Raton, Florida, 2003; Section 1, Basic Constants, Units, and Conversion Factors; Electron Configuration of Neutral Atoms in the Ground State. (elements 1–104)
Also subsection Periodic Table of the Elements, (elements 1–103) based on:
- G. J. Leigh, Editor, Nomenclature of Inorganic Chemistry, Blackwell Scientific Publications, Oxford, 1990.
- Chemical and Engineering News, 63(5), 27, 1985.
- Atomic Weights of the Elements, 1999, Pure Appl. Chem., 73, 667, 2001.

WebElements

http://www.webelements.com/ ; retrieved July 2005, electron configurations based on:
- Atomic, Molecular, & Optical Physics Handbook, Ed. Gordon W. F. Drake, American Institute of Physics, Woodbury, New York, 1996.
- J.E. Huheey, E.A. Keiter, and R.L. Keiter in Inorganic Chemistry : Principles of Structure and Reactivity, 4th edition, Harper Collins, New York, 1993.
- R.L. DeKock and H.B. Gray in Chemical Structure and bonding, Benjamin/Cummings, Menlo Park, California, 1980.
- A.M. James and M.P. Lord in Macmillan's Chemical and Physical Data, Macmillan, London, UK, 1992.
103 Lr : [Rn].5f¹⁴.7s².7p¹ tentative ; 2.8.18.32.32.9.2 [inconsistent]
104 Rf : [Rn].5f¹⁴.6d².7s² tentative
105 Db : [Rn].5f¹⁴.6d³.7s² (a guess based upon that of tantalum) ; 2.8.18.32.32.11.2
106 Sg : [Rn].5f¹⁴.6d⁴.7s² (a guess based upon that of tungsten) ; 2.8.18.32.32.12.2
107 Bh : [Rn].5f¹⁴.6d⁵.7s² (a guess based upon that of rhenium) ; 2.8.18.32.32.13.2
108 Hs : [Rn].5f¹⁴.6d⁶.7s² (a guess based upon that of osmium) ; 2.8.18.32.32.14.2
109 Mt : [Rn].5f¹⁴.6d⁷.7s² (a guess based upon that of iridium) ; 2.8.18.32.32.15.2
110 Ds : [Rn].5f¹⁴.6d⁹.7s¹ (a guess based upon that of platinum) ; 2.8.18.32.32.17.1
111 Rg : [Rn].5f¹⁴.6d¹⁰.7s¹ (a guess based upon that of gold) ; 2.8.18.32.32.18.1
112 Cn : [Rn].5f¹⁴.6d¹⁰.7s² (a guess based upon that of mercury) ; 2.8.18.32.32.18.2
113 Nh : [Rn].5f¹⁴.6d¹⁰.7s².7p¹ (a guess based upon that of thallium) ; 2.8.18.32.32.18.3
114 Fl : [Rn].5f¹⁴.6d¹⁰.7s².7p² (a guess based upon that of lead) ; 2.8.18.32.32.18.4
115 Mc : [Rn].5f¹⁴.6d¹⁰.7s².7p³ (a guess based upon that of bismuth) ; 2.8.18.32.32.18.5
116 Lv : [Rn].5f¹⁴.6d¹⁰.7s².7p⁴ (a guess based upon that of polonium) ; 2.8.18.32.32.18.6
117 Ts : [Rn].5f¹⁴.6d¹⁰.7s².7p⁵ (a guess based upon that of astatine) ; 2.8.18.32.32.18.7
118 Og : [Rn].5f¹⁴.6d¹⁰.7s².7p⁶ (a guess based upon that of radon) ; 2.8.18.32.32.18.8

Lange

J.A. Dean (ed), Lange's Handbook of Chemistry (15th Edition), online version, McGraw-Hill, 1999; Section 4, Table 4.1 Electronic Configuration and Properties of the Elements. (Elements 1–103)
97 Bk : [Rn] 5f⁸ 6d 7s²
103 Lr : [Rn] 4f¹⁴ [sic] 6d 7s²

Hill and Petrucci

Hill and Petrucci, General Chemistry: An Integrated Approach (3rd edition), Prentice Hall. (Elements 1–106)
58 Ce : [Xe] 4f² 6s²
103 Lr : [Rn] 5f¹⁴ 6d¹ 7s²
104 Rf : [Rn] 5f¹⁴ 6d² 7s² (agrees with guess above)
105 Db : [Rn] 5f¹⁴ 6d³ 7s²
106 Sg : [Rn] 5f¹⁴ 6d⁴ 7s²

Hoffman, Lee, and Pershina

Hoffman, Darleane C.; Lee, Diana M.; Pershina, Valeria (2006). "Transactinides and the future elements". In Morss; Edelstein, Norman M.; Fuger, Jean (eds.). The Chemistry of the Actinide and Transactinide Elements (3rd ed.). Dordrecht, The Netherlands: Springer Science+Business Media. p. 1722. ISBN 1-4020-3555-1.

This book contains predicted electron configurations for the elements up to 172, as well as 184, based on relativistic Dirac–Fock calculations by B. Fricke in Fricke, B. (1975). Dunitz, J. D. (ed.). "Superheavy elements a prediction of their chemical and physical properties". Structure and Bonding. 21. Berlin: Springer-Verlag: 89–144. doi:10.1007/BFb0116496. ISBN 978-3-540-07109-9.

[Jorgensen-1] Jørgensen, Christian K. (1988). "Influence of rare earths on chemical understanding and classification". Handbook on the Physics and Chemistry of Rare Earths. Vol. 11. pp. 197–292. doi:10.1016/S0168-1273(88)11007-6. ISBN 9780444870803.

[2] Nefedov, V. I.; Trzhaskovskaya, M. B.; Yarzhemskii, V. G. (2006). "Electronic Configurations and the Periodic Table for Superheavy Elements" (PDF). Doklady Physical Chemistry. 408 (Part 2). Pleaides Publishing: 149–151. doi:10.1134/S0012501606060029. S2CID 95738861. Retrieved 25 September 2020. configuration interaction is crucial in more than 30% of cases since its consideration leads to another ground-state configuration.

[1]

[2]