Periodic table (electron configurations)

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 2 14 3 -

106 Sg 2 14 4 -

107 Bh 2 14 5 -

108 Hs 2 14 6 -

109 Mt 2 14 7 -

110 Ds 2 14 8 -

111 Rg 2 14 9 -

112 Cn 2 14 10 -

113 Uut 2 14 10 1

114 Uuq 2 14 10 2

115 Uup 2 14 10 3

116 Uuh 2 14 10 4

117 Uus 2 14 10 5

118 Uuo 2 14 10 6

• Configurations of elements 105 and above are uncertain or not available. Predictions from reliable sources have been used for these elements. When no predictions are available, the electron configurations are guessed to be similar to the element directly above them.
• Grayed out electron numbers indicate subshells that are filled to their maximum.
• 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.

Element categories in the periodic table

Metals						Metalloids	Nonmetals			Unknown chemical properties
Alkali metals	Alkaline earth metals	Inner transition metals		Transition metals	Post-transition metals		Other non-metals	Halogens	Noble gases
		Lanthanides	Actinides

References

• Electron configurations of the elements (data page)