Electron configurations of the neutral gaseous atoms in the ground state.

1s:

1 H 1

2 He 2

[He] + 2s: 2p:

3 Li 1 -

4 Be 2 -

5 B 2 1

6 C 2 2

7 N 2 3

8 O 2 4

9 F 2 5

10 Ne 2 6

[Ne] + 3s: 3p:

11 Na 1 -

12 Mg 2 -

13 Al 2 1

14 Si 2 2

15 P 2 3

16 S 2 4

17 Cl 2 5

18 Ar 2 6

[Ar] + 4s: 3d: 4p:

19 K 1 - -

20 Ca 2 - -

21 Sc 2 1 -

22 Ti 2 2 -

23 V 2 3 -

24 Cr 1 5 -

25 Mn 2 5 -

26 Fe 2 6 -

27 Co 2 7 -

28 Ni 2 8 -

29 Cu 1 10 -

30 Zn 2 10 -

31 Ga 2 10 1

32 Ge 2 10 2

33 As 2 10 3

34 Se 2 10 4

35 Br 2 10 5

36 Kr 2 10 6

[Kr] + 5s: 4d: 5p:

37 Rb 1 - -

38 Sr 2 - -

39 Y 2 1 -

40 Zr 2 2 -

41 Nb 1 4 -

42 Mo 1 5 -

43 Tc 2 5 -

44 Ru 1 7 -

45 Rh 1 8 -

46 Pd - 10 -

47 Ag 1 10 -

48 Cd 2 10 -

49 In 2 10 1

50 Sn 2 10 2

51 Sb 2 10 3

52 Te 2 10 4

53 I 2 10 5

54 Xe 2 10 6

[Xe] + 6s: 4f: 5d: 6p:

55 Cs 1 - - -

56 Ba 2 - - -

57 La 2 - 1 -

58 Ce 2 1 1 -

59 Pr 2 3 - -

60 Nd 2 4 - -

61 Pm 2 5 - -

62 Sm 2 6 - -

63 Eu 2 7 - -

64 Gd 2 7 1 -

65 Tb 2 9 - -

66 Dy 2 10 - -

67 Ho 2 11 - -

68 Er 2 12 - -

69 Tm 2 13 - -

70 Yb 2 14 - -

71 Lu 2 14 1 -

72 Hf 2 14 2 -

73 Ta 2 14 3 -

74 W 2 14 4 -

75 Re 2 14 5 -

76 Os 2 14 6 -

77 Ir 2 14 7 -

78 Pt 1 14 9 -

79 Au 1 14 10 -

80 Hg 2 14 10 -

81 Tl 2 14 10 1

82 Pb 2 14 10 2

83 Bi 2 14 10 3

84 Po 2 14 10 4

85 At 2 14 10 5

86 Rn 2 14 10 6

[Rn] + 7s: 5f: 6d: 7p:

87 Fr 1 - - -

88 Ra 2 - - -

89 Ac 2 - 1 -

90 Th 2 - 2 -

91 Pa 2 2 1 -

92 U 2 3 1 -

93 Np 2 4 1 -

94 Pu 2 6 - -

95 Am 2 7 - -

96 Cm 2 7 1 -

97 Bk 2 9 - -

98 Cf 2 10 - -

99 Es 2 11 - -

100 Fm 2 12 - -

101 Md 2 13 - -

102 No 2 14 - -

103 Lr 2 14 - 1

104 Rf 2 14 2 -

105 Db

106 Sg

107 Bh

108 Hs

109 Mt

110 Ds

111 Rg

112 Uub

113 Uut

114 Uuq

115 Uup

116 Uuh

117 Uus

118 Uuo

• Configurations of elements with light gray background are uncertain or not available.

• Grayed out electron numbers indicate subshells that are filled to their maximum.

Configurations that are unavailable are guessed to be similar to the element directly above on the Periodic Table.

• The bracketed noble gas symbols on the left represent the inner configurations that are the same in each period. Written out these are:

He, 2, helium : 1s²

Ne, 10, neon : 1s² 2s² 2p⁶

Ar, 18, argon : 1s² 2s² 2p⁶ 3s² 3p⁶

Kr, 36, krypton : 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶

Xe, 54, xenon : 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶

Rn, 86, radon : 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶

Uuo, 118, Ununoctium : 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴ 6d¹⁰ 7p⁶

• Note the non-linear shell ordering, which comes about due to the different energies of smaller and larger shells.

References

electron configurations of the elements (data page)