Periodic table

118 elements

Displayed property

Temperature20 °C

Known by2009Ancient elements remain visible.

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Data for all 118 elements

Reference table: atomic number, symbol, name, atomic weight (or bracketed mass number), group, period, block and electron configuration.

Z	Symbol	Element	Atomic weight	Group	Period	Block	Electron configuration
1	H	Hydrogen	1.0080 ± 0.0002	1	1	s	1s1
2	He	Helium	4.0026 ± 0.0001	18	1	s	1s2
3	Li	Lithium	6.94 ± 0.06	1	2	s	[He]2s1
4	Be	Beryllium	9.0122 ± 0.0001	2	2	s	[He]2s2
5	B	Boron	10.81 ± 0.02	13	2	p	[He]2s2, 2p1
6	C	Carbon	12.011 ± 0.002	14	2	p	[He]2s2, 2p2
7	N	Nitrogen	14.007 ± 0.001	15	2	p	[He]2s2, 2p3
8	O	Oxygen	15.999 ± 0.001	16	2	p	[He]2s2, 2p4
9	F	Fluorine	18.998 ± 0.001	17	2	p	[He]2s2, 2p5
10	Ne	Neon	20.180 ± 0.001	18	2	p	[He]2s2, 2p6
11	Na	Sodium	22.990 ± 0.001	1	3	s	[Ne]3s1
12	Mg	Magnesium	24.305 ± 0.002	2	3	s	[Ne]3s2
13	Al	Aluminium	26.982 ± 0.001	13	3	p	[Ne]3s2, 3p1
14	Si	Silicon	28.085 ± 0.001	14	3	p	[Ne]3s2, 3p2
15	P	Phosphorus	30.974 ± 0.001	15	3	p	[Ne]3s2, 3p3
16	S	Sulfur	32.06 ± 0.02	16	3	p	[Ne]3s2, 3p4
17	Cl	Chlorine	35.45 ± 0.01	17	3	p	[Ne]3s2, 3p5
18	Ar	Argon	39.95 ± 0.16	18	3	p	[Ne]3s2, 3p6
19	K	Potassium	39.098 ± 0.001	1	4	s	[Ar]4s1
20	Ca	Calcium	40.078 ± 0.004	2	4	s	[Ar]4s2
21	Sc	Scandium	44.956 ± 0.001	3	4	d	[Ar]4s2, 3d1
22	Ti	Titanium	47.867 ± 0.001	4	4	d	[Ar]4s2, 3d2
23	V	Vanadium	50.942 ± 0.001	5	4	d	[Ar]4s2, 3d3
24	Cr	Chromium	51.996 ± 0.001	6	4	d	[Ar]4s1, 3d5
25	Mn	Manganese	54.938 ± 0.001	7	4	d	[Ar]4s2, 3d5
26	Fe	Iron	55.845 ± 0.002	8	4	d	[Ar]4s2, 3d6
27	Co	Cobalt	58.933 ± 0.001	9	4	d	[Ar]4s2, 3d7
28	Ni	Nickel	58.693 ± 0.001	10	4	d	[Ar]4s2, 3d8
29	Cu	Copper	63.546 ± 0.003	11	4	d	[Ar]4s1, 3d10
30	Zn	Zinc	65.38 ± 0.02	12	4	d	[Ar]4s2, 3d10
31	Ga	Gallium	69.723 ± 0.001	13	4	p	[Ar]4s2, 3d10, 4p1
32	Ge	Germanium	72.630 ± 0.008	14	4	p	[Ar]4s2, 3d10, 4p2
33	As	Arsenic	74.922 ± 0.001	15	4	p	[Ar]4s2, 3d10, 4p3
34	Se	Selenium	78.971 ± 0.008	16	4	p	[Ar]4s2, 3d10, 4p4
35	Br	Bromine	79.904 ± 0.003	17	4	p	[Ar]4s2, 3d10, 4p5
36	Kr	Krypton	83.798 ± 0.002	18	4	p	[Ar]4s2, 3d10, 4p6
37	Rb	Rubidium	85.468 ± 0.001	1	5	s	[Kr]5s1
38	Sr	Strontium	87.62 ± 0.01	2	5	s	[Kr]5s2
39	Y	Yttrium	88.906 ± 0.001	3	5	d	[Kr]5s2, 4d1
40	Zr	Zirconium	91.222 ± 0.003	4	5	d	[Kr]5s2, 4d2
41	Nb	Niobium	92.906 ± 0.001	5	5	d	[Kr]5s1, 4d4
42	Mo	Molybdenum	95.95 ± 0.01	6	5	d	[Kr]5s1, 4d5
43	Tc	Technetium	[97]	7	5	d	[Kr]5s2, 4d5
44	Ru	Ruthenium	101.07 ± 0.02	8	5	d	[Kr]5s1, 4d7
45	Rh	Rhodium	102.91 ± 0.01	9	5	d	[Kr]5s1, 4d8
46	Pd	Palladium	106.42 ± 0.01	10	5	d	[Kr]4d10
47	Ag	Silver	107.87 ± 0.01	11	5	d	[Kr]5s1, 4d10
48	Cd	Cadmium	112.41 ± 0.01	12	5	d	[Kr]5s2, 4d10
49	In	Indium	114.82 ± 0.01	13	5	p	[Kr]5s2, 4d10, 5p1
50	Sn	Tin	118.71 ± 0.01	14	5	p	[Kr]5s2, 4d10, 5p2
51	Sb	Antimony	121.76 ± 0.01	15	5	p	[Kr]5s2, 4d10, 5p3
52	Te	Tellurium	127.60 ± 0.03	16	5	p	[Kr]5s2, 4d10, 5p4
53	I	Iodine	126.90 ± 0.01	17	5	p	[Kr]5s2, 4d10, 5p5
54	Xe	Xenon	131.29 ± 0.01	18	5	p	[Kr]5s2, 4d10, 5p6
55	Cs	Caesium	132.91 ± 0.01	1	6	s	[Xe]6s1
56	Ba	Barium	137.33 ± 0.01	2	6	s	[Xe]6s2
57	La	Lanthanum	138.91 ± 0.01	3	6	d	[Xe]6s2, 5d1
58	Ce	Cerium	140.12 ± 0.01	3	6	f	[Xe]6s2, 4f1, 5d1
59	Pr	Praseodymium	140.91 ± 0.01	3	6	f	[Xe]6s2, 4f3
60	Nd	Neodymium	144.24 ± 0.01	3	6	f	[Xe]6s2, 4f4
61	Pm	Promethium	[145]	3	6	f	[Xe]6s2, 4f5
62	Sm	Samarium	150.36 ± 0.02	3	6	f	[Xe]6s2, 4f6
63	Eu	Europium	151.96 ± 0.01	3	6	f	[Xe]6s2, 4f7
64	Gd	Gadolinium	157.25 ± 0.01	3	6	f	[Xe]6s2, 4f7, 5d1
65	Tb	Terbium	158.93 ± 0.01	3	6	f	[Xe]6s2, 4f9
66	Dy	Dysprosium	162.50 ± 0.01	3	6	f	[Xe]6s2, 4f10
67	Ho	Holmium	164.93 ± 0.01	3	6	f	[Xe]6s2, 4f11
68	Er	Erbium	167.26 ± 0.01	3	6	f	[Xe]6s2, 4f12
69	Tm	Thulium	168.93 ± 0.01	3	6	f	[Xe]6s2, 4f13
70	Yb	Ytterbium	173.05 ± 0.02	3	6	f	[Xe]6s2, 4f14
71	Lu	Lutetium	174.97 ± 0.01	3	6	f	[Xe]6s2, 4f14, 5d1
72	Hf	Hafnium	178.49 ± 0.01	4	6	d	[Xe]6s2, 4f14, 5d2
73	Ta	Tantalum	180.95 ± 0.01	5	6	d	[Xe]6s2, 4f14, 5d3
74	W	Tungsten	183.84 ± 0.01	6	6	d	[Xe]6s2, 4f14, 5d4
75	Re	Rhenium	186.21 ± 0.01	7	6	d	[Xe]6s2, 4f14, 5d5
76	Os	Osmium	190.23 ± 0.03	8	6	d	[Xe]6s2, 4f14, 5d6
77	Ir	Iridium	192.22 ± 0.01	9	6	d	[Xe]6s2, 4f14, 5d7
78	Pt	Platinum	195.08 ± 0.02	10	6	d	[Xe]6s1, 4f14, 5d9
79	Au	Gold	196.97 ± 0.01	11	6	d	[Xe]6s1, 4f14, 5d10
80	Hg	Mercury	200.59 ± 0.01	12	6	d	[Xe]6s2, 4f14, 5d10
81	Tl	Thallium	204.38 ± 0.01	13	6	p	[Xe]6s2, 4f14, 5d10, 6p1
82	Pb	Lead	207.2 ± 1.1	14	6	p	[Xe]6s2, 4f14, 5d10, 6p2
83	Bi	Bismuth	208.98 ± 0.01	15	6	p	[Xe]6s2, 4f14, 5d10, 6p3
84	Po	Polonium	[209]	16	6	p	[Xe]6s2, 4f14, 5d10, 6p4
85	At	Astatine	[210]	17	6	p	[Xe]6s2, 4f14, 5d10, 6p5
86	Rn	Radon	[222]	18	6	p	[Xe]6s2, 4f14, 5d10, 6p6
87	Fr	Francium	[223]	1	7	s	[Rn]7s1
88	Ra	Radium	[226]	2	7	s	[Rn]7s2
89	Ac	Actinium	[227]	3	7	d	[Rn]7s2, 6d1
90	Th	Thorium	232.04 ± 0.01	3	7	f	[Rn]7s2, 6d2
91	Pa	Protactinium	231.04 ± 0.01	3	7	f	[Rn]7s2, 5f2, 6d1
92	U	Uranium	238.03 ± 0.01	3	7	f	[Rn]7s2, 5f3, 6d1
93	Np	Neptunium	[237]	3	7	f	[Rn]7s2, 5f4, 6d1
94	Pu	Plutonium	[244]	3	7	f	[Rn]7s2, 5f6
95	Am	Americium	[243]	3	7	f	[Rn]7s2, 5f7
96	Cm	Curium	[247]	3	7	f	[Rn]7s2, 5f7, 6d1
97	Bk	Berkelium	[247]	3	7	f	[Rn]7s2, 5f9
98	Cf	Californium	[251]	3	7	f	[Rn]7s2, 5f10
99	Es	Einsteinium	[252]	3	7	f	[Rn]7s2, 5f11
100	Fm	Fermium	[257]	3	7	f	[Rn]7s2, 5f12
101	Md	Mendelevium	[258]	3	7	f	[Rn]7s2, 5f13
102	No	Nobelium	[259]	3	7	f	[Rn]7s2, 5f14
103	Lr	Lawrencium	[262]	3	7	f	[Rn]7s2, 5f14, 7p1
104	Rf	Rutherfordium	[267]	4	7	d	[Rn]7s2, 5f14, 6d2
105	Db	Dubnium	[268]	5	7	d	[Rn]7s2, 5f14, 6d3
106	Sg	Seaborgium	[269]	6	7	d	[Rn]7s2, 5f14, 6d4
107	Bh	Bohrium	[270]	7	7	d	[Rn]7s2, 5f14, 6d5
108	Hs	Hassium	[269]	8	7	d	[Rn]7s2, 5f14, 6d6
109	Mt	Meitnerium	[277]	9	7	d	[Rn]7s2, 5f14, 6d7
110	Ds	Darmstadtium	[281]	10	7	d	[Rn]7s2, 5f14, 6d8
111	Rg	Roentgenium	[282]	11	7	d	[Rn]7s2, 5f14, 6d9
112	Cn	Copernicium	[285]	12	7	d	[Rn]7s2, 5f14, 6d10
113	Nh	Nihonium	[286]	13	7	p	[Rn]7s2, 5f14, 6d10, 7p1
114	Fl	Flerovium	[290]	14	7	p	[Rn]7s2, 5f14, 6d10, 7p2
115	Mc	Moscovium	[290]	15	7	p	[Rn]7s2, 5f14, 6d10, 7p3
116	Lv	Livermorium	[293]	16	7	p	[Rn]7s2, 5f14, 6d10, 7p4
117	Ts	Tennessine	[294]	17	7	p	[Rn]7s2, 5f14, 6d10, 7p5
118	Og	Oganesson	[294]	18	7	p	[Rn]7s2, 5f14, 6d10, 7p6

Periodic trends

Atomic radius, electronegativity, and ionization energy vary with electron structure. Across a period, increasing effective nuclear charge pulls valence electrons more strongly; down a group, additional occupied shells change atomic size and shielding.

Compare two elements

Side-by-side comparison is useful across a period, down a group, or between neighbours. Na/K, C/Si, and F/Cl make the effect of position on several atomic properties immediately visible.

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