Periodic table of electron affinity

Interactive periodic table of electron affinity in kJ/mol. ElementWorks is a free interactive periodic table: hover an element to preview it, click it for its full card, or pick another view from the Show menu.

Periodic table of electron affinity explained

Electron affinity is the energy released when a gaseous atom gains an electron. Larger values mean the atom holds an extra electron more strongly. The halogens have the largest values, with chlorine highest, which is why they readily form 1− ions. Noble gases and group 2 elements have little or no affinity, so they are left blank or near zero here.

Highest values

Chlorine (Cl): 349 kJ/mol
Fluorine (F): 328 kJ/mol
Bromine (Br): 324.6 kJ/mol
Iodine (I): 295.2 kJ/mol
Astatine (At): 270 kJ/mol

Lowest values

Calcium (Ca): 2.4 kJ/mol
Strontium (Sr): 5 kJ/mol
Titanium (Ti): 7.6 kJ/mol
Barium (Ba): 14 kJ/mol
Hafnium (Hf): 14.5 kJ/mol

Data table

Show the full data table (all 118 elements)

Electron affinity (kJ/mol) of all 118 elements
No.	Symbol	Element	Electron affinity (kJ/mol)
1	H	Hydrogen	72.8 kJ/mol
2	He	Helium	—
3	Li	Lithium	59.6 kJ/mol
4	Be	Beryllium	—
5	B	Boron	26.7 kJ/mol
6	C	Carbon	121.8 kJ/mol
7	N	Nitrogen	—
8	O	Oxygen	141 kJ/mol
9	F	Fluorine	328 kJ/mol
10	Ne	Neon	—
11	Na	Sodium	52.8 kJ/mol
12	Mg	Magnesium	—
13	Al	Aluminium	42.5 kJ/mol
14	Si	Silicon	134.1 kJ/mol
15	P	Phosphorus	72 kJ/mol
16	S	Sulfur	200.4 kJ/mol
17	Cl	Chlorine	349 kJ/mol
18	Ar	Argon	—
19	K	Potassium	48.4 kJ/mol
20	Ca	Calcium	2.4 kJ/mol
21	Sc	Scandium	18.1 kJ/mol
22	Ti	Titanium	7.6 kJ/mol
23	V	Vanadium	50.6 kJ/mol
24	Cr	Chromium	64.3 kJ/mol
25	Mn	Manganese	—
26	Fe	Iron	15.7 kJ/mol
27	Co	Cobalt	63.7 kJ/mol
28	Ni	Nickel	112 kJ/mol
29	Cu	Copper	118.4 kJ/mol
30	Zn	Zinc	—
31	Ga	Gallium	41 kJ/mol
32	Ge	Germanium	119 kJ/mol
33	As	Arsenic	78 kJ/mol
34	Se	Selenium	195 kJ/mol
35	Br	Bromine	324.6 kJ/mol
36	Kr	Krypton	—
37	Rb	Rubidium	46.9 kJ/mol
38	Sr	Strontium	5 kJ/mol
39	Y	Yttrium	29.6 kJ/mol
40	Zr	Zirconium	41.1 kJ/mol
41	Nb	Niobium	86.1 kJ/mol
42	Mo	Molybdenum	71.9 kJ/mol
43	Tc	Technetium	53 kJ/mol
44	Ru	Ruthenium	101.3 kJ/mol
45	Rh	Rhodium	109.7 kJ/mol
46	Pd	Palladium	53.7 kJ/mol
47	Ag	Silver	125.6 kJ/mol
48	Cd	Cadmium	—
49	In	Indium	29 kJ/mol
50	Sn	Tin	107.3 kJ/mol
51	Sb	Antimony	101 kJ/mol
52	Te	Tellurium	190.2 kJ/mol
53	I	Iodine	295.2 kJ/mol
54	Xe	Xenon	—
55	Cs	Cesium	45.5 kJ/mol
56	Ba	Barium	14 kJ/mol
57	La	Lanthanum	—
58	Ce	Cerium	—
59	Pr	Praseodymium	—
60	Nd	Neodymium	—
61	Pm	Promethium	—
62	Sm	Samarium	—
63	Eu	Europium	—
64	Gd	Gadolinium	—
65	Tb	Terbium	—
66	Dy	Dysprosium	—
67	Ho	Holmium	—
68	Er	Erbium	—
69	Tm	Thulium	—
70	Yb	Ytterbium	—
71	Lu	Lutetium	—
72	Hf	Hafnium	14.5 kJ/mol
73	Ta	Tantalum	31 kJ/mol
74	W	Tungsten	78.6 kJ/mol
75	Re	Rhenium	14.5 kJ/mol
76	Os	Osmium	106.1 kJ/mol
77	Ir	Iridium	151 kJ/mol
78	Pt	Platinum	205.3 kJ/mol
79	Au	Gold	222.8 kJ/mol
80	Hg	Mercury	—
81	Tl	Thallium	19.2 kJ/mol
82	Pb	Lead	35.1 kJ/mol
83	Bi	Bismuth	91.2 kJ/mol
84	Po	Polonium	183 kJ/mol
85	At	Astatine	270 kJ/mol
86	Rn	Radon	—
87	Fr	Francium	—
88	Ra	Radium	—
89	Ac	Actinium	—
90	Th	Thorium	—
91	Pa	Protactinium	—
92	U	Uranium	—
93	Np	Neptunium	—
94	Pu	Plutonium	—
95	Am	Americium	—
96	Cm	Curium	—
97	Bk	Berkelium	—
98	Cf	Californium	—
99	Es	Einsteinium	—
100	Fm	Fermium	—
101	Md	Mendelevium	—
102	No	Nobelium	—
103	Lr	Lawrencium	—
104	Rf	Rutherfordium	—
105	Db	Dubnium	—
106	Sg	Seaborgium	—
107	Bh	Bohrium	—
108	Hs	Hassium	—
109	Mt	Meitnerium	—
110	Ds	Darmstadtium	—
111	Rg	Roentgenium	—
112	Cn	Copernicium	—
113	Nh	Nihonium	—
114	Fl	Flerovium	—
115	Mc	Moscovium	—
116	Lv	Livermorium	—
117	Ts	Tennessine	—
118	Og	Oganesson	—

Frequently asked questions

Which element has the highest electron affinity?

Chlorine, at about 349 kJ/mol. Fluorine is slightly lower because its small size causes strong electron-electron repulsion.

Why do halogens have high electron affinities?

One extra electron completes their valence shell, giving a stable noble-gas configuration, so energy is released.

Is electron affinity the same as electronegativity?

No. Electron affinity is an energy for gaining an electron by a single gaseous atom. Electronegativity describes how strongly an atom attracts electrons within a chemical bond.