Configuration électronique des 118 éléments

La répartition des électrons de chaque atome dans ses sous-couches, et le nombre d'électrons par couche.

La configuration électronique décrit comment les électrons d'un atome se répartissent dans les sous-couches s, p, d et f autour du noyau. On l'écrit de façon abrégée à partir du gaz noble qui précède : le fer, [Ar] 3d⁶ 4s², a les électrons de l'argon plus huit autres.

Les sous-couches se remplissent en général dans l'ordre de la règle de Klechkowski (1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d…), avec quelques exceptions, comme le chrome ([Ar] 3d⁵ 4s¹) et le cuivre ([Ar] 3d¹⁰ 4s¹). C'est la couche externe qui fixe la place d'un élément dans le tableau et l'essentiel de sa chimie : les éléments d'une même colonne ont la même structure externe.

Voir les couches électroniques en 3D sur chaque fiche →

N°	Symbole	Nom	Configuration	Électrons par couche	Bloc
1	H	Hydrogène	1s¹	1	s
2	He	Hélium	1s²	2	s
3	Li	Lithium	[He] 2s¹	2, 1	s
4	Be	Béryllium	[He] 2s²	2, 2	s
5	B	Bore	[He] 2s² 2p¹	2, 3	p
6	C	Carbone	[He] 2s² 2p²	2, 4	p
7	N	Azote	[He] 2s² 2p³	2, 5	p
8	O	Oxygène	[He] 2s² 2p⁴	2, 6	p
9	F	Fluor	[He] 2s² 2p⁵	2, 7	p
10	Ne	Néon	[He] 2s² 2p⁶	2, 8	p
11	Na	Sodium	[Ne] 3s¹	2, 8, 1	s
12	Mg	Magnésium	[Ne] 3s²	2, 8, 2	s
13	Al	Aluminium	[Ne] 3s² 3p¹	2, 8, 3	p
14	Si	Silicium	[Ne] 3s² 3p²	2, 8, 4	p
15	P	Phosphore	[Ne] 3s² 3p³	2, 8, 5	p
16	S	Soufre	[Ne] 3s² 3p⁴	2, 8, 6	p
17	Cl	Chlore	[Ne] 3s² 3p⁵	2, 8, 7	p
18	Ar	Argon	[Ne] 3s² 3p⁶	2, 8, 8	p
19	K	Potassium	[Ar] 4s¹	2, 8, 8, 1	s
20	Ca	Calcium	[Ar] 4s²	2, 8, 8, 2	s
21	Sc	Scandium	[Ar] 3d¹ 4s²	2, 8, 9, 2	d
22	Ti	Titane	[Ar] 3d² 4s²	2, 8, 10, 2	d
23	V	Vanadium	[Ar] 3d³ 4s²	2, 8, 11, 2	d
24	Cr	Chrome	[Ar] 3d⁵ 4s¹	2, 8, 13, 1	d
25	Mn	Manganèse	[Ar] 3d⁵ 4s²	2, 8, 13, 2	d
26	Fe	Fer	[Ar] 3d⁶ 4s²	2, 8, 14, 2	d
27	Co	Cobalt	[Ar] 3d⁷ 4s²	2, 8, 15, 2	d
28	Ni	Nickel	[Ar] 3d⁸ 4s²	2, 8, 16, 2	d
29	Cu	Cuivre	[Ar] 3d¹⁰ 4s¹	2, 8, 18, 1	d
30	Zn	Zinc	[Ar] 3d¹⁰ 4s²	2, 8, 18, 2	d
31	Ga	Gallium	[Ar] 3d¹⁰ 4s² 4p¹	2, 8, 18, 3	p
32	Ge	Germanium	[Ar] 3d¹⁰ 4s² 4p²	2, 8, 18, 4	p
33	As	Arsenic	[Ar] 3d¹⁰ 4s² 4p³	2, 8, 18, 5	p
34	Se	Sélénium	[Ar] 3d¹⁰ 4s² 4p⁴	2, 8, 18, 6	p
35	Br	Brome	[Ar] 3d¹⁰ 4s² 4p⁵	2, 8, 18, 7	p
36	Kr	Krypton	[Ar] 3d¹⁰ 4s² 4p⁶	2, 8, 18, 8	p
37	Rb	Rubidium	[Kr] 5s¹	2, 8, 18, 8, 1	s
38	Sr	Strontium	[Kr] 5s²	2, 8, 18, 8, 2	s
39	Y	Yttrium	[Kr] 4d¹ 5s²	2, 8, 18, 9, 2	d
40	Zr	Zirconium	[Kr] 4d² 5s²	2, 8, 18, 10, 2	d
41	Nb	Niobium	[Kr] 4d⁴ 5s¹	2, 8, 18, 12, 1	d
42	Mo	Molybdène	[Kr] 4d⁵ 5s¹	2, 8, 18, 13, 1	d
43	Tc	Technétium	[Kr] 4d⁵ 5s²	2, 8, 18, 13, 2	d
44	Ru	Ruthénium	[Kr] 4d⁷ 5s¹	2, 8, 18, 15, 1	d
45	Rh	Rhodium	[Kr] 4d⁸ 5s¹	2, 8, 18, 16, 1	d
46	Pd	Palladium	[Kr] 4d¹⁰	2, 8, 18, 18	d
47	Ag	Argent	[Kr] 4d¹⁰ 5s¹	2, 8, 18, 18, 1	d
48	Cd	Cadmium	[Kr] 4d¹⁰ 5s²	2, 8, 18, 18, 2	d
49	In	Indium	[Kr] 4d¹⁰ 5s² 5p¹	2, 8, 18, 18, 3	p
50	Sn	Étain	[Kr] 4d¹⁰ 5s² 5p²	2, 8, 18, 18, 4	p
51	Sb	Antimoine	[Kr] 4d¹⁰ 5s² 5p³	2, 8, 18, 18, 5	p
52	Te	Tellure	[Kr] 4d¹⁰ 5s² 5p⁴	2, 8, 18, 18, 6	p
53	I	Iode	[Kr] 4d¹⁰ 5s² 5p⁵	2, 8, 18, 18, 7	p
54	Xe	Xénon	[Kr] 4d¹⁰ 5s² 5p⁶	2, 8, 18, 18, 8	p
55	Cs	Césium	[Xe] 6s¹	2, 8, 18, 18, 8, 1	s
56	Ba	Baryum	[Xe] 6s²	2, 8, 18, 18, 8, 2	s
57	La	Lanthane	[Xe] 5d¹ 6s²	2, 8, 18, 18, 9, 2	f
58	Ce	Cérium	[Xe] 4f¹ 5d¹ 6s²	2, 8, 18, 19, 9, 2	f
59	Pr	Praséodyme	[Xe] 4f³ 6s²	2, 8, 18, 21, 8, 2	f
60	Nd	Néodyme	[Xe] 4f⁴ 6s²	2, 8, 18, 22, 8, 2	f
61	Pm	Prométhium	[Xe] 4f⁵ 6s²	2, 8, 18, 23, 8, 2	f
62	Sm	Samarium	[Xe] 4f⁶ 6s²	2, 8, 18, 24, 8, 2	f
63	Eu	Europium	[Xe] 4f⁷ 6s²	2, 8, 18, 25, 8, 2	f
64	Gd	Gadolinium	[Xe] 4f⁷ 5d¹ 6s²	2, 8, 18, 25, 9, 2	f
65	Tb	Terbium	[Xe] 4f⁹ 6s²	2, 8, 18, 27, 8, 2	f
66	Dy	Dysprosium	[Xe] 4f¹⁰ 6s²	2, 8, 18, 28, 8, 2	f
67	Ho	Holmium	[Xe] 4f¹¹ 6s²	2, 8, 18, 29, 8, 2	f
68	Er	Erbium	[Xe] 4f¹² 6s²	2, 8, 18, 30, 8, 2	f
69	Tm	Thulium	[Xe] 4f¹³ 6s²	2, 8, 18, 31, 8, 2	f
70	Yb	Ytterbium	[Xe] 4f¹⁴ 6s²	2, 8, 18, 32, 8, 2	f
71	Lu	Lutécium	[Xe] 4f¹⁴ 5d¹ 6s²	2, 8, 18, 32, 9, 2	d
72	Hf	Hafnium	[Xe] 4f¹⁴ 5d² 6s²	2, 8, 18, 32, 10, 2	d
73	Ta	Tantale	[Xe] 4f¹⁴ 5d³ 6s²	2, 8, 18, 32, 11, 2	d
74	W	Tungstène	[Xe] 4f¹⁴ 5d⁴ 6s²	2, 8, 18, 32, 12, 2	d
75	Re	Rhénium	[Xe] 4f¹⁴ 5d⁵ 6s²	2, 8, 18, 32, 13, 2	d
76	Os	Osmium	[Xe] 4f¹⁴ 5d⁶ 6s²	2, 8, 18, 32, 14, 2	d
77	Ir	Iridium	[Xe] 4f¹⁴ 5d⁷ 6s²	2, 8, 18, 32, 15, 2	d
78	Pt	Platine	[Xe] 4f¹⁴ 5d⁹ 6s¹	2, 8, 18, 32, 17, 1	d
79	Au	Or	[Xe] 4f¹⁴ 5d¹⁰ 6s¹	2, 8, 18, 32, 18, 1	d
80	Hg	Mercure	[Xe] 4f¹⁴ 5d¹⁰ 6s²	2, 8, 18, 32, 18, 2	d
81	Tl	Thallium	[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p¹	2, 8, 18, 32, 18, 3	p
82	Pb	Plomb	[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p²	2, 8, 18, 32, 18, 4	p
83	Bi	Bismuth	[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p³	2, 8, 18, 32, 18, 5	p
84	Po	Polonium	[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁴	2, 8, 18, 32, 18, 6	p
85	At	Astate	[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵	2, 8, 18, 32, 18, 7	p
86	Rn	Radon	[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁶	2, 8, 18, 32, 18, 8	p
87	Fr	Francium	[Rn] 7s¹	2, 8, 18, 32, 18, 8, 1	s
88	Ra	Radium	[Rn] 7s²	2, 8, 18, 32, 18, 8, 2	s
89	Ac	Actinium	[Rn] 6d¹ 7s²	2, 8, 18, 32, 18, 9, 2	f
90	Th	Thorium	[Rn] 6d² 7s²	2, 8, 18, 32, 18, 10, 2	f
91	Pa	Protactinium	[Rn] 5f² 6d¹ 7s²	2, 8, 18, 32, 20, 9, 2	f
92	U	Uranium	[Rn] 5f³ 6d¹ 7s²	2, 8, 18, 32, 21, 9, 2	f
93	Np	Neptunium	[Rn] 5f⁴ 6d¹ 7s²	2, 8, 18, 32, 22, 9, 2	f
94	Pu	Plutonium	[Rn] 5f⁶ 7s²	2, 8, 18, 32, 24, 8, 2	f
95	Am	Américium	[Rn] 5f⁷ 7s²	2, 8, 18, 32, 25, 8, 2	f
96	Cm	Curium	[Rn] 5f⁷ 6d¹ 7s²	2, 8, 18, 32, 25, 9, 2	f
97	Bk	Berkélium	[Rn] 5f⁹ 7s²	2, 8, 18, 32, 27, 8, 2	f
98	Cf	Californium	[Rn] 5f¹⁰ 7s²	2, 8, 18, 32, 28, 8, 2	f
99	Es	Einsteinium	[Rn] 5f¹¹ 7s²	2, 8, 18, 32, 29, 8, 2	f
100	Fm	Fermium	[Rn] 5f¹² 7s²	2, 8, 18, 32, 30, 8, 2	f
101	Md	Mendélévium	[Rn] 5f¹³ 7s²	2, 8, 18, 32, 31, 8, 2	f
102	No	Nobélium	[Rn] 5f¹⁴ 7s²	2, 8, 18, 32, 32, 8, 2	f
103	Lr	Lawrencium	[Rn] 5f¹⁴ 7s² 7p¹	2, 8, 18, 32, 32, 8, 3	d
104	Rf	Rutherfordium	[Rn] 5f¹⁴ 6d² 7s²	2, 8, 18, 32, 32, 10, 2	d
105	Db	Dubnium	[Rn] 5f¹⁴ 6d³ 7s²	2, 8, 18, 32, 32, 11, 2	d
106	Sg	Seaborgium	[Rn] 5f¹⁴ 6d⁴ 7s²	2, 8, 18, 32, 32, 12, 2	d
107	Bh	Bohrium	[Rn] 5f¹⁴ 6d⁵ 7s²	2, 8, 18, 32, 32, 13, 2	d
108	Hs	Hassium	[Rn] 5f¹⁴ 6d⁶ 7s²	2, 8, 18, 32, 32, 14, 2	d
109	Mt	Meitnérium	[Rn] 5f¹⁴ 6d⁷ 7s²	2, 8, 18, 32, 32, 15, 2	d
110	Ds	Darmstadtium	[Rn] 5f¹⁴ 6d⁸ 7s²	2, 8, 18, 32, 32, 16, 2	d
111	Rg	Roentgenium	[Rn] 5f¹⁴ 6d⁹ 7s²	2, 8, 18, 32, 32, 17, 2	d
112	Cn	Copernicium	[Rn] 5f¹⁴ 6d¹⁰ 7s²	2, 8, 18, 32, 32, 18, 2	d
113	Nh	Nihonium	[Rn] 5f¹⁴ 6d¹⁰ 7s² 7p¹	2, 8, 18, 32, 32, 18, 3	p
114	Fl	Flérovium	[Rn] 5f¹⁴ 6d¹⁰ 7s² 7p²	2, 8, 18, 32, 32, 18, 4	p
115	Mc	Moscovium	[Rn] 5f¹⁴ 6d¹⁰ 7s² 7p³	2, 8, 18, 32, 32, 18, 5	p
116	Lv	Livermorium	[Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁴	2, 8, 18, 32, 32, 18, 6	p
117	Ts	Tennesse	[Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁵	2, 8, 18, 32, 32, 18, 7	p
118	Og	Oganesson	[Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁶	2, 8, 18, 32, 32, 18, 8	p