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 Fl 2 14 10 2	115 Uup 2 14 10 3	116 Lv 2 14 10 4	117 Uus 2 14 10 5	118 Uuo 2 14 10 6

Legend for the background color

Background color shows subcategory in the metal–metalloid–nonmetal trend: Metal Metalloid Nonmetal Unknown chemical properties Alkali metal Alkaline earth metal Lan­thanide Actinide Transition metal Post-​transition metal Polyatomic nonmetal Diatomic nonmetal Noble gas

• 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)