Periodic table (electron configurations)

Group:

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

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
Nh
2
14
10
1

114
Fl
2
14
10
2

115
Mc
2
14
10
3

116
Lv
2
14
10
4

117
Ts
2
14
10
5

118
Og
2
14
10
6

Configurations of elements 103 and 104 are uncertain; those for elements 105 and above are not available. Predictions from reliable sources have been used for these elements.
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.

References

Electron configurations of the elements (data page)