Electron Configuration

Search 1–92 by atomic number, symbol, or name, then compare condensed notation, the full configuration, and electrons per shell.

Neutral ground states, H–U: configurations follow the cited NIST table. Ions, excited states, orbital-box diagrams, and predicted superheavy elements are outside this page.

Or browse all 92 elements

Choose an element to see its condensed and full configuration.

Electron configuration chart

All 92 neutral atoms from hydrogen through uranium.

Swipe for configurations and shells

Neutral ground-state electron configurations, hydrogen through uranium
Z	Element	Condensed configuration	Shells
1	HHydrogen	`1s¹`	`1`
2	HeHelium	`1s²`	`2`
3	LiLithium	`[He] 2s¹`	`2–1`
4	BeBeryllium	`[He] 2s²`	`2–2`
5	BBoron	`[He] 2s² 2p¹`	`2–3`
6	CCarbon	`[He] 2s² 2p²`	`2–4`
7	NNitrogen	`[He] 2s² 2p³`	`2–5`
8	OOxygen	`[He] 2s² 2p⁴`	`2–6`
9	FFluorine	`[He] 2s² 2p⁵`	`2–7`
10	NeNeon	`[He] 2s² 2p⁶`	`2–8`
11	NaSodium	`[Ne] 3s¹`	`2–8–1`
12	MgMagnesium	`[Ne] 3s²`	`2–8–2`
13	AlAluminum	`[Ne] 3s² 3p¹`	`2–8–3`
14	SiSilicon	`[Ne] 3s² 3p²`	`2–8–4`
15	PPhosphorus	`[Ne] 3s² 3p³`	`2–8–5`
16	SSulfur	`[Ne] 3s² 3p⁴`	`2–8–6`
17	ClChlorine	`[Ne] 3s² 3p⁵`	`2–8–7`
18	ArArgon	`[Ne] 3s² 3p⁶`	`2–8–8`
19	KPotassium	`[Ar] 4s¹`	`2–8–8–1`
20	CaCalcium	`[Ar] 4s²`	`2–8–8–2`
21	ScScandium	`[Ar] 3d¹ 4s²`	`2–8–9–2`
22	TiTitanium	`[Ar] 3d² 4s²`	`2–8–10–2`
23	VVanadium	`[Ar] 3d³ 4s²`	`2–8–11–2`
24	CrChromium	`[Ar] 3d⁵ 4s¹`	`2–8–13–1`
25	MnManganese	`[Ar] 3d⁵ 4s²`	`2–8–13–2`
26	FeIron	`[Ar] 3d⁶ 4s²`	`2–8–14–2`
27	CoCobalt	`[Ar] 3d⁷ 4s²`	`2–8–15–2`
28	NiNickel	`[Ar] 3d⁸ 4s²`	`2–8–16–2`
29	CuCopper	`[Ar] 3d¹⁰ 4s¹`	`2–8–18–1`
30	ZnZinc	`[Ar] 3d¹⁰ 4s²`	`2–8–18–2`
31	GaGallium	`[Ar] 3d¹⁰ 4s² 4p¹`	`2–8–18–3`
32	GeGermanium	`[Ar] 3d¹⁰ 4s² 4p²`	`2–8–18–4`
33	AsArsenic	`[Ar] 3d¹⁰ 4s² 4p³`	`2–8–18–5`
34	SeSelenium	`[Ar] 3d¹⁰ 4s² 4p⁴`	`2–8–18–6`
35	BrBromine	`[Ar] 3d¹⁰ 4s² 4p⁵`	`2–8–18–7`
36	KrKrypton	`[Ar] 3d¹⁰ 4s² 4p⁶`	`2–8–18–8`
37	RbRubidium	`[Kr] 5s¹`	`2–8–18–8–1`
38	SrStrontium	`[Kr] 5s²`	`2–8–18–8–2`
39	YYttrium	`[Kr] 4d¹ 5s²`	`2–8–18–9–2`
40	ZrZirconium	`[Kr] 4d² 5s²`	`2–8–18–10–2`
41	NbNiobium	`[Kr] 4d⁴ 5s¹`	`2–8–18–12–1`
42	MoMolybdenum	`[Kr] 4d⁵ 5s¹`	`2–8–18–13–1`
43	TcTechnetium	`[Kr] 4d⁵ 5s²`	`2–8–18–13–2`
44	RuRuthenium	`[Kr] 4d⁷ 5s¹`	`2–8–18–15–1`
45	RhRhodium	`[Kr] 4d⁸ 5s¹`	`2–8–18–16–1`
46	PdPalladium	`[Kr] 4d¹⁰`	`2–8–18–18`
47	AgSilver	`[Kr] 4d¹⁰ 5s¹`	`2–8–18–18–1`
48	CdCadmium	`[Kr] 4d¹⁰ 5s²`	`2–8–18–18–2`
49	InIndium	`[Kr] 4d¹⁰ 5s² 5p¹`	`2–8–18–18–3`
50	SnTin	`[Kr] 4d¹⁰ 5s² 5p²`	`2–8–18–18–4`
51	SbAntimony	`[Kr] 4d¹⁰ 5s² 5p³`	`2–8–18–18–5`
52	TeTellurium	`[Kr] 4d¹⁰ 5s² 5p⁴`	`2–8–18–18–6`
53	IIodine	`[Kr] 4d¹⁰ 5s² 5p⁵`	`2–8–18–18–7`
54	XeXenon	`[Kr] 4d¹⁰ 5s² 5p⁶`	`2–8–18–18–8`
55	CsCesium	`[Xe] 6s¹`	`2–8–18–18–8–1`
56	BaBarium	`[Xe] 6s²`	`2–8–18–18–8–2`
57	LaLanthanum	`[Xe] 5d¹ 6s²`	`2–8–18–18–9–2`
58	CeCerium	`[Xe] 4f¹ 5d¹ 6s²`	`2–8–18–19–9–2`
59	PrPraseodymium	`[Xe] 4f³ 6s²`	`2–8–18–21–8–2`
60	NdNeodymium	`[Xe] 4f⁴ 6s²`	`2–8–18–22–8–2`
61	PmPromethium	`[Xe] 4f⁵ 6s²`	`2–8–18–23–8–2`
62	SmSamarium	`[Xe] 4f⁶ 6s²`	`2–8–18–24–8–2`
63	EuEuropium	`[Xe] 4f⁷ 6s²`	`2–8–18–25–8–2`
64	GdGadolinium	`[Xe] 4f⁷ 5d¹ 6s²`	`2–8–18–25–9–2`
65	TbTerbium	`[Xe] 4f⁹ 6s²`	`2–8–18–27–8–2`
66	DyDysprosium	`[Xe] 4f¹⁰ 6s²`	`2–8–18–28–8–2`
67	HoHolmium	`[Xe] 4f¹¹ 6s²`	`2–8–18–29–8–2`
68	ErErbium	`[Xe] 4f¹² 6s²`	`2–8–18–30–8–2`
69	TmThulium	`[Xe] 4f¹³ 6s²`	`2–8–18–31–8–2`
70	YbYtterbium	`[Xe] 4f¹⁴ 6s²`	`2–8–18–32–8–2`
71	LuLutetium	`[Xe] 4f¹⁴ 5d¹ 6s²`	`2–8–18–32–9–2`
72	HfHafnium	`[Xe] 4f¹⁴ 5d² 6s²`	`2–8–18–32–10–2`
73	TaTantalum	`[Xe] 4f¹⁴ 5d³ 6s²`	`2–8–18–32–11–2`
74	WTungsten	`[Xe] 4f¹⁴ 5d⁴ 6s²`	`2–8–18–32–12–2`
75	ReRhenium	`[Xe] 4f¹⁴ 5d⁵ 6s²`	`2–8–18–32–13–2`
76	OsOsmium	`[Xe] 4f¹⁴ 5d⁶ 6s²`	`2–8–18–32–14–2`
77	IrIridium	`[Xe] 4f¹⁴ 5d⁷ 6s²`	`2–8–18–32–15–2`
78	PtPlatinum	`[Xe] 4f¹⁴ 5d⁹ 6s¹`	`2–8–18–32–17–1`
79	AuGold	`[Xe] 4f¹⁴ 5d¹⁰ 6s¹`	`2–8–18–32–18–1`
80	HgMercury	`[Xe] 4f¹⁴ 5d¹⁰ 6s²`	`2–8–18–32–18–2`
81	TlThallium	`[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p¹`	`2–8–18–32–18–3`
82	PbLead	`[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p²`	`2–8–18–32–18–4`
83	BiBismuth	`[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p³`	`2–8–18–32–18–5`
84	PoPolonium	`[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁴`	`2–8–18–32–18–6`
85	AtAstatine	`[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵`	`2–8–18–32–18–7`
86	RnRadon	`[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁶`	`2–8–18–32–18–8`
87	FrFrancium	`[Rn] 7s¹`	`2–8–18–32–18–8–1`
88	RaRadium	`[Rn] 7s²`	`2–8–18–32–18–8–2`
89	AcActinium	`[Rn] 6d¹ 7s²`	`2–8–18–32–18–9–2`
90	ThThorium	`[Rn] 6d² 7s²`	`2–8–18–32–18–10–2`
91	PaProtactinium	`[Rn] 5f² 6d¹ 7s²`	`2–8–18–32–20–9–2`
92	UUranium	`[Rn] 5f³ 6d¹ 7s²`	`2–8–18–32–21–9–2`

Private by design: searches and selected elements stay in this page. They are not saved, added to the URL, or included in analytics.

The complete condensed chart works without JavaScript. Turn on JavaScript to search, expand full configurations, compare adjacent elements, or copy notation.

By Wei Chieh Liao · Updated September 21, 2026. Element lookups run in your browser.

How to read an electron configuration

Each term names a subshell. In 3d⁶, 3 is the principal shell, d is the subshell, and the superscript 6 is the number of electrons there. Add every superscript in a neutral atom's full configuration and the total should equal its atomic number. The result card performs that check again as an electrons-by-shell sum.

Condensed notation and full notation

Condensed notation begins with a noble-gas core in brackets, which keeps long configurations readable. Full notation expands that core. For iron, [Ar] 3d⁶ 4s² and 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁶ 4s² describe the same 26 electrons. Use the copy buttons when you need either form for notes or homework.

Compare nearby elements

After a lookup, use the previous and next element buttons to see what changes across adjacent atomic numbers. The full chart also shows shell totals, so you can compare the distribution across principal shells without expanding every noble-gas core yourself.

Known ground-state exceptions stay intact

A simple Aufbau or diagonal-rule exercise is useful for learning, but it does not reproduce every measured neutral ground state. This page stores the cited NIST values rather than correcting exceptions into a predicted pattern. Examples include chromium, copper, niobium, molybdenum, palladium, platinum, and gold.

Scope, source, and privacy

The NIST table is the source for every configuration. This page recursively expands each bracketed noble-gas core, converts exponents to readable superscripts, and totals electrons by principal shell; the PubChem link supplies a broader periodic-table reference for element identity. The reference covers neutral ground-state atoms from hydrogen (Z = 1) through uranium (Z = 92). It does not calculate ions, excited states, orbital box diagrams, quantum numbers, or predicted configurations for elements beyond uranium. The records are built into the page, so searches run locally and do not call an element-data service.

Frequently asked questions

What is an electron configuration?

An electron configuration records how a neutral atom's electrons occupy subshells such as 1s, 2s, 2p, and 3d. A superscript gives the number of electrons in that subshell.

What does the bracketed noble gas mean?

Condensed notation replaces the filled inner subshells with the preceding noble gas in brackets. For example, copper is [Ar] 3d¹⁰ 4s¹; [Ar] stands for argon's 18-electron configuration.

Why do chromium and copper look different from a simple filling-order prediction?

Measured neutral ground states include exceptions to a basic diagonal-rule exercise. This chart uses the NIST configurations directly, including chromium as [Ar] 3d⁵ 4s¹ and copper as [Ar] 3d¹⁰ 4s¹.

Does this chart show ions?

No. It covers neutral ground-state atoms from hydrogen through uranium. Ion configurations depend on charge and are outside this page.

Why does the full configuration list 3d before 4s?

The display follows the order used by the cited NIST table. That order groups occupied subshells by shell and subshell rather than teaching an electron-filling sequence.