Ionization energy

Ionization energy is the energy needed to ionize an atom in the gas phase. Ionization leads to a positive electrical charge. All data are given for individual atoms in electron volts (eV).

Element		Ionization energy [eV]
₁H	Hydrogen	13.598
₂He	Helium	24.587	54.417	24.587	54.417
₃Li	Lithium	5.3917	75.64	122.45
₄Be	Beryllium	9.3226	18.211	153.89	217.71
₅B	Boron	8.298	25.154	37.93	259.37	340.22
₆C	Carbon	11.26	24.383	47.887	64.493	392.09
₇N	Nitrogen	14.534	29.601	47.445	77.473	97.89
₈O	Oxygen	13.618	35.121	54.935	77.413	113.89	138.11
₉F	Fluorine	17.422	34.97	62.707	87.175	114.24	157.16	185.18
₁₀Ne	Neon	21.564	40.962	63.423	97.19	126.24
₁₁Na	Sodium	5.139	47.286	71.62	98.936	138.4
₁₂Mg	Magnesium	7.6462	15.035	80.143	109.26	141.33
₁₃Al	Aluminum	5.9857	18.828	28.447	119.99	153.82
₁₄Si	Silicon	8.1516	16.345	33.493	45.141	166.76
₁₅P	Phosphorus	10.486	19.769	30.202	51.443	65.025
₁₆S	Sulfur	10.36	23.337	34.86	47.222	72.594	88.052
₁₇Cl	Chlorine	12.967	23.813	39.8	53.24	67.68	96.94	114.2
₁₈Ar	Argon	15.759	27.629	40.735	59.58	74.84
₁₉K	Potassium	4.3406	31.625	45.803	60.917	82.66
₂₀Ca	Calcium	6.1131	11.871	50.913	67.273	84.34
₂₁Sc	Scandium	6.5614	12.799	24.756	73.489	91.95
₂₂Ti	Titanium	6.8281	13.575	27.491	43.267	99.299
₂₃V	Vanadium	6.7461	14.634	29.311	46.709	65.281
₂₄Cr	Chromium	6.7665	16.486	30.959	49.16	69.46
₂₅Mn	Manganese	7.434	15.639	33.668	51.21	72.41
₂₆Fe	Iron	7.9024	16.199	30.651	54.91	75
₂₇Co	Cobalt	7.881	17.084	33.5	51.27	79.5
₂₈Ni	Nickel	7.6398	18.168	35.187	54.92	76.06
₂₉Cu	Copper	7.7263	20.292	36.841	57.38	79.8
₃₀Zn	Zinc	9.3941	17.964	39.723	59.573	82.6
₃₁Ga	Gallium	5.9993	20.515	30.725	63.241	86.01
₃₂Ge	Germanium	7.8994	15.934	34.057	45.715	90.5
₃₃As	Arsenic	9.7885	18.589	28.349	50.15	62.77
₃₄Se	Selenium	9.7523	21.196	31.697	42.947	68.3	81.83
₃₅Br	Bromine	11.813	21.591	34.871	47.782	59.595	87.39	103.03
₃₆Kr	Krypton	13.999	24.359	35.838	50.85	64.69
₃₇Rb	Rubidium	4.1771	27.289	39.247	52.2	68.44
₃₈Sr	Strontium	5.6948	11.03	42.883	56.28	70.7
₃₉Y	Yttrium	6.2172	12.223	20.524	60.607	75.35
₄₀Zr	Zirconium	6.6341	13.13	23.17	34.418	80.348
₄₁Nb	Niobium	6.7588	14.32	25.04	37.611	50.572
₄₂Mo	Molybdenum	7.0924	16.16	27.13	40.33	54.417
₄₃Tc	Technetium	7.1193	15.26	29.55	41	57
₄₄Ru	Ruthenium	7.3605	16.76	28.47	45	59
₄₅Rh	Rhodium	7.4589	18.08	31.06	42	63
₄₆Pd	Palladium	8.3368	19.43	32.93	46	61
₄₇Ag	Silver	7.5762	21.484	34.8	49	65
₄₈Cd	Cadmium	8.9938	16.908	37.468	51	67.9
₄₉In	Indium	5.7863	18.87	28.044	55.45	69.3
₅₀Sn	Tin	7.3439	14.633	30.506	40.74	77.03
₅₁Sb	Antimony	8.6083	16.626	25.323	43.804	55
₅₂Te	Tellurium	9.0098	18.6	27.84	37.415	59.3	69.1
₅₃I	Iodine	10.451	19.131	29.57	40.357	51.52	74.4	87.61
₅₄Xe	Xenon	12.129	20.975	31.05	42.2	54.1
₅₅Cs	Caesium	3.8939	23.157	33.195	43	56
₅₆Ba	Barium	5.2116	10.003	35.843	47	58
₅₇La	Lanthanum	5.5769	11.184	19.177	49.95	61.6
₅₈Ce	Cerium	5.5386	10.956	20.197	36.906	65.55
₅₉Pr	Praseodymium	5.4702	10.631	21.623	39.981	57.53
₆₀Nd	Neodymium	5.525	10.783	22.09	40.6	60
₆₁Pm	Promethium	5.5818	10.938	22.44	41.17	61.7
₆₂Sm	Samarium	5.6437	11.078	23.55	41.64	62.7
₆₃Eu	Europium	5.6703	11.24	24.84	42.94	63.2
₆₄Gd	Gadolinium	6.1498	12.076	20.54	44.44	64.8
₆₅Tb	Terbium	5.8638	11.513	21.82	39.33	66.5
₆₆Dy	Dysprosium	5.939	11.647	22.89	41.23	62.1
₆₇Ho	Holmium	6.0215	11.781	22.79	42.52	63.9
₆₈Er	Erbium	6.1077	11.916	22.7	42.42	65.1
₆₉Tm	Thulium	6.1843	12.065	23.66	42.41	65.4
₇₀Yb	Ytterbium	6.2541	12.179	25.053	43.61	65.6
₇₁Lu	Lutetium	5.4258	14.13	20.959	45.249	66.8
₇₂Hf	Hafnium	6.825	114.61	22.55	33.37	68.37
₇₃Ta	Tantalum	7.5495	16.2	32.1	35	48.272
₇₄W	Tungsten	7.864	16.37	26	38.2	51.6
₇₅Re	Rhenium	7.8335	16.6	27	39.1	51.9
₇₆Os	Osmium	8.4382	17	25	41	55
₇₇Ir	Iridium	8.967	17	28	40	57
₇₈Pt	Platinum	8.9588	18.56	29	43	56
₇₉Au	Gold	9.2255	20.203	30	45	60
₈₀Hg	Mercury	10.437	18.756	34.49	48.55	61.2
₈₁Tl	Thallium	6.1082	20.428	29.852	51.14	62.6
₈₂Pb	Lead	7.4166	15.032	31.937	42.332	68.8
₈₃Bi	Bismuth	7.2855	16.703	25.563	45.37	54.856
₈₄Po	Polonium	8.418	19.3	27.3	36	57	69.1
₈₅At	Astatine	9.3175	17.88	26.58	39.65	50.39	72	85.1
₈₆Rn	Radon	10.748	21.4	29.4	36.9	52.9
₈₇Fr	Francium	4.0727	22.4	33.5	39.1	50
₈₈Ra	Radium	5.2784	10.147	31	41	52.9
₈₉Ac	Actinium	5.3802	11.75	17.431	44.8	55
₉₀Th	Thorium	6.3067	12.1	18.32	28.648	58
₉₁Pa	Protactinium	5.89	11.9	18.6	30.9	44.3
₉₂U	Uranium	6.194	11.6	19.8	36.7	46
₉₃Np	Neptunium	6.2655	11.5	19.7	33.8	48
₉₄Pu	Plutonium	6.0257	11.5	21.1	35	49
₉₅Am	Americium	5.9738	11.7	21.7	36.8	50
₉₆Cm	Curium	5.9914	12.4	20.1	37.7	51
₉₇Bk	Berkelium	6.1978	11.9	21.6	36	56
₉₈Cf	Californium	6.2816	12	22.4	37.7	51.9
₉₉Es	Einsteinium	6.3675	12.2	22.7	38.8	54.1
₁₀₀Fm	Fermium	(6.5)	(12.4)	(23.2)	(39.3)	(55)
₁₀₁Md	Mendelevium	(6.58)	(12.4)	(24.3)	(40)	(54.1)
₁₀₂No	Nobelium	(6.6262)	(12.93)	(25.8)	(41.5)	(60)
₁₀₃Lr	Lawrencium	(4.96)	(14.54)	(21.8)	(43.6)	(56)
₁₀₄Rf	Rutherfordium	(6.02)	(14.35)	(23.84)	(31.87)	(64)
₁₀₅Db	Dubnium	(6.8)	(14)	(23.1)	(33)	(43)
₁₀₆Sg	Seaborgium	(7.8)	(17.1)	(25.8)	(35.5)	(47.2)
₁₀₇Bh	Bohrium	(7.7)	(17.5)	(26.7)	(37.3)	(49)
₁₀₈Hs	Hassium	(7.6)	(18.2)	(29.3)	(37.7)	(51.2)
₁₀₉Mt	Meitnerium	(8.3)
₁₁₀Ds	Darmstadtium	(9.9)
₁₁₁Rg	Roentgenium	(10.6)
₁₁₂Cn	Copernicium	(12)
₁₁₃Nh	Nihonium	(7.31)
₁₁₄Fl	Flerovium	(8.54)
₁₁₅Mc	Moscovium	(5.57)
₁₁₆Lv	Livermorium	(7.5)
₁₁₇Ts	Tennessine	(7.7)
₁₁₈Og	Oganesson	(8.7)